GMAT Verbal Reasoning Practice Test 1

The proportion of Afro-American students enrolled in Gilmore Community College has increased over the past decades. This is partly shown by the fact that in 1965, only 6 percent of Afro-American between twenty and twenty-three in the town of Gilmore were enrolled in college, while in 1997, 13 percent of the Afro-Americans between twenty and twenty-three were enrolled in Gilmore Community College. To evaluate the argument above, it would be most useful to compare 1965 and 1997 with regard to which of the following characteristics