In the years from 1950 to 1955, only a few countries had a level of life expectancy greater than 70 years, and only 1.0 per cent of the world’s population lived in such countries. At that time, 71.9 per cent of the world’s population lived in countries where the life expectancy at birth was less than 60 years (figure 1). The reductions of mortality since the middle of the twentieth century have been so substantial that the proportion of the population living in countries with a life expectancy below 60 years had decreased to only 8.5 per cent for the period between 2010 and 2015.