The gaps are narrowing but there is still a big difference in being 81 years old or only 59 years old as a average in the population.
A main reason for the smaller gaps are improvements in child mortality
The biggest gaps:
Swaziland 49 years – Japan 84 years in 2014 / in 1990: 59 (!) and 79
The decline in Swaziland primarily refers to AIDS – Swaziland is one of the most affected countries in the World.