Yes, comparing body wounds is useful, but I'm looking at the "whole picture" as it were. Against a knife you're less likely to receive a wound of that sort.
I've known a couple guys that took minor wounds they deflected or partially dodged. I bet many knife wounds never get reported to a hospital to get into those statistics, compared to few bullet wounds.
A couple guys I've known who were good with a knife were…I wouldn't say they aren't fit to live among us, but they had problems and I wasn't eager to be buddies with 'em.