India has experienced steady population growth since 1921. It is currently the second most populous country in the world with over 1.2 billion people. The population is young, with more than 30% under 15 years old. This is reflected in India's demographic pyramid which shows a broad base tapering at the top. Sex ratios are improving but remain unbalanced due to cultural preferences for sons. Most states have ratios below national average of 940 females per 1000 males. Literacy and education levels are increasing but large proportions still lack basic education. Life expectancy is also rising but remains lower than developed nations. The population is projected to surpass China's by 2027 and reach 1.53 billion by 2050.