From what I found, there are almost twice as many 22lr thefts than there are 9mm. Another factor is the $100 Saturday Night Specials that are still being sold in high numbers. Also, everyone is only looking at "in the commission of a crime" stats. What about justifiable homicides, and even accidental deaths?
Until I got into tag along real-time police investigation shows Like The Shift, The First 48, DateLine, etc, I would not have guessed that 22lr were used as much as they are in accual shootings. I searched, but
the only recent data in from 2011 that only pertains to California, and that data does not show deaths. It only shows what firearms were used in crimes, like robberies or pistol whippings, but may have not resulted in any death or discharge from the firearm.
What I found from actual cases, instead of relying on hearsay, hypothesis, and ballistic data, is that when someone is shot in their vital organs with a 22lr or any other caliber, many of then die regardless of the caliber. I've seen video footage where people were shot by various calibers, and in some cases, they were able to communicate and functioned for a while before later succumbing to their wounds either on the scene or at the hospital. Some that were shot by 40cals were able to run door to door begging for help before dying... I think stopping power relative to shot placement, and the physical characteristics of the person shot. Someone shot in the heart with a 9mm/40 may drop on the spot, and others may keep moving...