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1. ASRAT WOLDEYES HEALTH SCIENCE
CAMPUS
SCHOOL OF PUBLIC HEALTH
DEPARTMENT OF PUBLIC HEALTH
COURSE TITLE: BIOSTATISTICS
COURSE CODE: ……………..........
SUBMITTEDTO: ZENEBEABEBE.(BScin PHO, MPH in Biostatistics
)
SUBMISSION DATE; 13/06/2016E.C
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2. OUT LINE
 OBJECTIVE
 INTRODACTION TO POPULATION PYRAMID
 STRUCTURE OF POPULATION PYRAMID
 INTERPRETATION OF POPULATION PYRAMIDS
 TYPES OF POPULATION PYRAMID
 IMPORTANCE OF POPULATION PYRAMIDS
 POPULATION PYRAMIDS IN ETHIOPIA
 REFERENCE AND CONCLUSION
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3. OBJECTIVE
• At the end of this section the student will be able to:-
• Define TO Population Pyramid
• Describe To structure Of Population Pyramid
• Explain Types of Population Pyramid
• Understand the Importance Of Population
Pyramids
• Explain about population pyramid in Ethiopia
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4. introduction
• A population pyramid : is a graphical representation
that shows the distribution of age groups and gender
within a population.
• These pyramids are essential tools for demographers,
sociologists, economists, and policymakers to understand
the composition and dynamics of a population.
• It also called age-sex pyramid the shape of a pyramid when
the population is growing.
• Males are usually shown on the left and females on the
right, young persons at the bottom, and elderly at the top.
they may be measured in absolute numbers or as a
percentage of the total population.
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5. Con…
• The pyramid can be used to visualize the age of a particular
population. It is also used in ecology to determine the
overall age distribution of a population; an indication of the
reproductive capabilities and likelihood of the continuation
of a species.
• Number of people per unit area of land Is
called population density.
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6. Structure of population pyramid
• A population pyramid often contains continuous stacked-
histogram bars, making it a horizontal bar diagram.
• The population size is shown on the x-axis (horizontal)
while the age-groups are represented on the y-axis
(vertical) the size of each bar can be displayed either as
a percentage of the total population or as a raw number.
• Males are conventionally shown on the left and females on
the right.
• Population pyramids are often viewed as the most effective
way to graphically depict the age and distribution of a
population, partly because of the very clear image these
pyramids provide.
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7. Con…
• The measures of central tendency (mean, median,
and mode) should be considered when assessing a
population pyramid. For example, the average age could be
used to determine the type of population in a particular
region.
• A series of population pyramids could give a clear picture
of how a country transitions from high to low fertility rates.
• If the pyramid has a broad base, this indicates that a
relatively high proportion of the population lies in the
youngest age band, such as ages 0–14, which suggests that
the fertility rate of the country is high and
above replacement fertility level.
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8. Con…
• If a population is below replacement fertility level, the older
population is declining with age, due to a combination of
mortality and an increase in the number of births over time.
• There are usually more females than males in the older age
ranges since, for a variety of reasons; women have a greater life
expectancy.
• The shape of the pyramid can also reveal the age-dependency
ratio of a population. Populations with a high proportion of
children and/or of elderly people have a higher dependency
ratio. This ratio refers to how many old and young people are
dependent on the working-age groups
• population pyramids can be used to predict the future, known
as a population forecast.
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9. Con…
• Lastly, a population pyramid can even give insight into the
economic status of a country from the age
stratification since the distribution of supplies is not evenly
distributed through a population.
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10. Interpretation of Population Pyramids
• 1. AgeDistribution: The width of the pyramid at each age group
reflects the size of the population within that cohort. A
broader base indicates a higher number of young people,
while a narrower top suggests fewer elderly individuals.
• 2. SexDistribution:When divided by gender, population
pyramids can reveal differences in the male and female
populations within each age group.
• 3. Dependency Ratios:By analyzing the relative sizes of young
and old cohorts in relation to the working-age population,
population pyramids can provide insights into the
potential support burden placed on the working-age
population.
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11. Types of population pyramid
• Each country will have a different population pyramid.
However, population pyramids can be categorized into
three types: stationary, expansive, or constrictive. These
types have been identified by the fertility and mortality
rates of a country.
1. STATIONARY PYRAMID ORCONSTANT POPULATIONPYRAMID
• A pyramid can be described as stationary if the percentages of
population (age and sex) remain approximately constant over
time. In a stationary population, the numbers of births and
death roughly balance one another.
• This pyramid suggests a stable population, characterized by a
fairly consistent birth rate, an older age structure, and a
potentially higher life expectancy.
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12. Con…
2. EXPANSIVE PYRAMID OREXPANDING POPULATIONPYRAMID
• A population pyramid that is very wide at the younger
ages, characteristic of countries with a high birth rate and
perhaps low life expectancy therefore leading to high death
rate.
• The population is said to be fast-growing, and the size of
each birth cohort increases each year.
• This pyramid has a broad base, indicating a high
proportion of younger individuals, with a gradually
narrowing profile as age groups progress upwards.
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13. con…
3.CONSTRICTIVE PYRAMIDORDECLININPOPULATION
• A population pyramid that is narrowed at the bottom.
• The population is generally older on average, as the
country has long life expectancy, a low death rate, but
also a low birth rate.
• This may suggest that in future there may be a high
dependency ratio due to reducing numbers at working
ages. This is a typical pattern for a very developed
country, with a high level of education, easy access to
and incentive to use birth control, good health care,
and few negative environmental factors.
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14. Con…
• Population pyramids of developing countries like Ethiopia
have very broad bases, showing the dominance of the
young-age population.
• These pyramids become increasingly narrower towards
the top, advancing through the age groups, showing that
the percentage of the population becomes less and less in
the upper age groups (65-69, 70-74, etc.
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15. Importance of Population Pyramids
• Population pyramids play a crucial role in understanding
demographic trends and making informed policy decisions.
They help governments, researchers, and policymakers:
• Here are some importance of population pyramids;
1. Analyze the current demographic structure of a
population, which can help in identifying potential issues
related to aging, dependency ratios, and workforce
availability.
2. Forecast future population trends, which can help in
planning for infrastructure, healthcare, education, and
social services.
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16. Con…
3 . Compare population trends across different countries or
regions, which can help in understanding global demographic
patterns and inform international policies.
4. Identify the impact of various demographic factors, such as
birth rates, death rates, and migration patterns, on population
growth and change.
5. Assess the sustainability of social and economic systems,
which can help in developing strategies to maintain a
balanced and healthy population.
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17. POPULATION PYRAMIDS IN ETHIOPIA
• The population pyramid of Ethiopia is a graphical
representation of the age and sex distribution of the country's
population.
• It shows the number of people in different age groups and their
gender.
• According to the United Nations Department of Economic and
Social Affairs Population Division, The estimated total
population of Ethiopia in 2024, based on the growth rate from
2016, is approximately 123 million.
• the structure of the population pyramid was slightly different in
1999 compared to today. The proportion of people in the
working-age group (15-64) was lower at around 63%, while the
percentage of children under 15 was higher at around 40%.
Additionally, there were more elderly individuals (aged 65+)
back then, making up around 7% of the total population.
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21. TOTALPOPULATIONPYRAMIDOFETHIOPIA:2024
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22. Con…
• Based on the population pyramids for Ethiopia in both
1999 and 2024, we can draw some conclusions about the
country's demographic trends:
• 1. Youthful population: Ethiopia has a relatively young
population, with around 67% of the population falling within the
working-age group in 2024. This is likely due to high fertility
rates in the past and improved healthcare contributing to longer
lifespans.
• 2. Decline in fertility rates: the difference between the two
population pyramids, that fertility rates have declined
significantly since 2024. This shift towards lower fertility rates
is expected to continue in the coming decades, although the pace
may vary depending on various factors such as education levels
and economic development.
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23. Con…
• 3. Aging population: with in 2024 As fertility rates decrease
and life expectancy increases, the proportion of elderly
individuals (aged 65+) will increase over time. In 1999, this age
group made up only around 7% of the total population, but by
2024, it had risen to around 8%. This trend is expected to
continue in the future as long as mortality rates remain low and
people live longer.
• 4. Changing gender dynamics: The population pyramid also
shows us shifting gender dynamics. For example, in 1999, there
were more men than women across all age groups, whereas in
2024, the opposite is true - there are now more women than
men under the age of 15. These changes reflect evolving social
norms and opportunities for women's empowerment.
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24. • 1. United Nations Department of Economic and Social
Affairs Population Division. (n.d.). World Population
Prospects: The 2019 Revision. Retrieved from
https://population.un.org/wpp/
• 2. https://ourworldindata.org/population-pyramids
• 3. WIKIPEDIA
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25. GROUP MEMBER
 NAME ID:NUMBER 1.FENTAHUN
ANIMAW...........................1402709 2.ENDASHAW
BUTA.................................1402665 3.GETABALEW
YISMAW.........................1402763
 4. FIKADU SHEWA.....................................1402730
5.FRESENBET DANEIL.............................1401279
6.YEHUALASHET NIGUSSIE...................1403116
 7.HIWOT JEJAW............................................1401408
 8.REDIET DEREB.........................................1402206
9.MEHARIW EWNETIE.............................1401658
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