i am 87 yrs old. finished 10th grade in 1947. got GED in Marine Corps 1949.
joined Mensa 1976/78. 134 IQ Self educated.
The vast difference in quality and content of an education from different eras, regions, schools and programs makes it very difficult to correlate any of this information presented here to the vague phrase "years of education." What was taught in the 6th grade in many places is now taught in high school. Likewise with college, where an AS or AA is really just grades 13 & 14 in much of the country.