My dad is 60 years old and was most obviously born in the very early 60's. His mother was born 1929, my grandmother died at the age of 90 in 2019. Most people that were in their 20's in the 50s are now in their 90s, right? WELL, anywho, since most people then were in their 20s-30s, as a random guess, I'd say 80-90%. I'm not good at math, sorry y'all.