That article was written almost a month before Trump's recent pardons, and only tallies through FY2020, ending Sept 30. In the meantime, trump has pardoned war criminals and several people who have done crimes on his behalf. In pretty much everything I've read on the subject, that is not the average sort of offender who is granted leniency.

A lack of a large number of pardons is no surprise, really. By all appearances, he's pardoning his partners in crime and war criminals. Traditionally, pardons are granted to folks who haven't gotten a fair shake, or whose sentences are disproportionate to their crimes. Contrast the number of pardons with the recent spree of executions -- this is all in line with the "tough on crime" narrative. Forget about justice, the goal is brutality and death to the enemy.