Life expectancy at birth reflects the overall mortality level of a population. It summarizes the mortality pattern that prevails across all age groups in a given year – children and adolescents, adults and the elderly. Global life expectancy at birth in 2015 was 71.4 years (73.8 years for females and 69.1 years for males), ranging from 60.0 years in the WHO African Region to 76.8 years in the WHO European Region, giving a ratio of 1.3 between the two regions. Women live longer than men all around the world. The gap in life expectancy between the sexes was 4.5 years in 1990 and had remained almost the same by 2015 (4.6). Global average life expectancy increased by 5 years between 2000 and 2015, the fastest increase since the 1960s. Those gains reverse declines during the 1990s, when life expectancy fell in Africa because of the AIDS epidemic, and in Eastern Europe following the collapse of the Soviet Union. The 2000-2015 increase was greatest in the WHO African Region, where life expectancy increased by 9.4 years to 60 years, driven mainly by improvements in child survival, and expanded access to antiretrovirals for treatment of HIV.
The World Health Organization (WHO) began producing annual life tables for all Member States in 1999. These life tables are a basic input to all WHO estimates of global, regional and country-level patterns and trends in all-cause and cause-specific mortality. After the publication of life tables for years to 2009 in the 2011 edition of World Health Statistics, WHO has shifted to a two year cycle for the updating of life tables for all Member States, and has moved towards alignment of this revision cycle with that of the World Population Prospects produced biennially by the UN Population Division.