"In tests of fourth-grade reading from 2000 to 2007, for instance, the scores of the lowest-achieving students increased by 16 points on a 280-point scale, comp

"In tests of fourth-grade reading from 2000 to 2007, for instance, the scores of the lowest-achieving students increased by 16 points on a 280-point scale, compared with a gain of three points for top-achieving students, according to the study, by the Thomas B. Fordham Institute, a research organization in Washington." Is it just me or does this seem normal? Is it not much harder for someone on top to improve vs. someone on the bottom? For example, a Michael Jordan who already spends considerable effort and energy being the best (having little more total time to work on improving), vs. someone who puts little time and effort (having much more time to contribute and therefore improve).