This stat is in George Gilder's "Wealth and Poverty" in the 1980s. For my book, "The Entreprenuerial Adventure: A History of Business in the U.S." (Harcourt, 2000: http://www.amazon.com/exec/obidos/tg/detail/-/0155084550/qid=1097498434/sr=1-2/ref=sr_1_2/102-6679035-8484967?v=glance&s=books) I looked at the Forbes 400 richest in 1990 and then again in either 1995 or 1998 (I forget) and looked at the number whose bios said they had not been to college or high school.