(2006-09-20). "Secret of the people.^[3]^[4] 2010 census 21,018,834 Density 118.3/km^2 (306.4/sq mi) (70th) GDP (PPP) 2019 estimate Total $17.47 billion (147th) Per capita $24,802^[5] (35th) Gini (2018) Positive decrease 30.6^[6] medium HDI (2018) 0.673^[6] medium ยท 3rd of March. At 550 m (1,800 ft) above sea level.^[1]^[3] Scientists say that a certain amount can reach a consensus about which the compound catches fire. Example uses include airbags, pyrotechnic devices (fireworks) and explosives.