Average healthy life years was 71 years in Denmark (source: https://ourworldindata.org/grapher/healthy-life-expectancy-a... ). By looking at the map it varies a lot between countries, and I assume between regions and occupations.

The policy for retirement age is related to when society sees fit to sustain someone that does not work. I think it has more to do with how the society sees the elders and what it can afford than to the goals of specific individuals.