Pakistan has the 7th largest population in the world, which was estimated to be 170 million in 2010 and projected to grow to 210 million by 2020. Approximately 33% of Pakistanis live below the poverty line, with rural areas experiencing higher poverty levels of 39%. Agriculture accounts for 25% of Pakistan's GDP and livestock engages between 30-34 million rural residents. The world population reached 1 billion in 1804, 5 billion in 1987, 6 billion in 1999, and is projected to reach 8 billion in 2020 and 9.2 billion by 2050.