Life expectancy is going up and up for the last century. Broadly speaking in Western countries, it is well over 80 years now when it was 70 years half a century ago, and it will be 90 in fifty years. It looks like each decade life expectancy in the west goes up 2 years.

If so, which part of our life is increasing? Are we 'young' longer than before? Is 'adult' life waht is increasing? Are we 'old' longer than before?