Average life expectancy at birth has increased by 6.4 years over the period 2000-2016 (63.2 years in 2000 and 69.6 years in 2016). Since 2000, the lowest life expectancy values are observed in Domod Aimag (58 years in 2000, 63.9 years in 2010 and 68.63 years in 2016) and Khuvsgul Aimag (59 years in 2000,63.6 years in 2010 and 66 years in 2016). In 2015, the major causes of death in under-5-year-olds were related to certain conditions originating in the perinatal period, congenital malformations, deformations and chromosomal abnormalities, and diseases of the respiratory system.