 Because child mortality has declined substantially over the last several decades, Global life expectancy at birth, which is estimated to have risen from 47 years in 1950–1955 to 67 years in 2000–2005, is expected to keep rising to reach 77 years in 2045–2050.In the More Developed regions, the projected increase is from 79 years today to 83 years by mid-century.Among the Least Developed countries, where life expectancy today is just under 65 years, it is expected to be 71 years in 2045–2050.