Looking at rebounds, per 40 minutes, his rebounding totals actually regressed from freshman to senior year: from 7.2 to 6.6.
For defense, in terms of basic metrics, his blocks and steals stats were basically static from freshman year to senior year (blocks: .4 to .4 per 40 min, steals: 1.1 to 1.7 per 40). In terms of advanced metrics, his defensive rating marginally improved from 102.5 to 103.1 from freshman to senior year, his defensive win shares grew from .9 to 1.2 and his overall defensive plus/minus was 1.6 FR year, 2.0 SO year, 2.0 JR year, and 1.6 his SR year.