They've averaged his total home run distance over his entire career. Towards the last few years, they've increased by an average of like 50 feet. And no, he wasn't the power hitter he was before the supposed steroids began.

His average yearly homerun total before the age of 30: ~27 homeruns
His average yearly homerun total after the age of 30: ~40 homeruns

By comparison, these are the similar totals for Hank Aaron:

His average yearly homerun total before the age of 30: ~33 homeruns
His average yearly homerun total after the age of 30: ~32 homeruns


Nobody gets that much stronger after the age of 30.