I would point out that 100 years ago (1919) universal secondary education was not the rule, many people, and in particular boys, did not progress beyond the eighth grade at the time. So you have in high schools of the time a system which had weeded out the poor performing students leaving only those academically able students. So the comparison is not really a valid one.
This was so much the case that during both World War I and II the military instituted programs to try and give soldiers and sailors the opportunity to complete their schooling while in the service. True universal secondary education like we have today would not really come into play until after the Second World War.
