This just in:
Why you should seriously consider the merits of a college education:A 2013 study based on Labor Department statistics showed that Americans holding a four-year college degree made 98% more per hour on average than those without a degree. - (CNN Money)
More recently, according to 2015 data compiled by the Economic Policy Institute, "college graduates, on average, earned 56% more" than those who only have a high-school diploma (USA Today).