It feels like a natural result of life expectancy increasing over 70 (world wide average) only in 2021 and a number of years past publication being required for

It feels like a natural result of life expectancy increasing over 70 (world wide average) only in 2021 and a number of years past publication being required for something to be deemed a major work means it is natural that there are few today. Something like 100%, 110%, and 120% if life expectancy at the author’s time of birth might be a more useful measure today.