EDIT: I read the source. Looks like mostly mountaineering/unroped accidents. Now I can delude myself again! Use protection!
“TECHNICAL DIFFICULTIES OF THE ROUTES Most climbers were hurt during climbs of lesser difficulty. (Table 3). The category of 5.1 to 5.3 yielded the highest number of accidents, injuries, and fatalities.
CLIMBING EXPERIENCE OF INJURED CLIMBERS Climbers with less experience appeared to be more frequently involved in accidents than were those with more experience. (It was possible to precisely determine the experience of the climbers in only about 50% of the accidents.) Of those climbers whose experience levels were known, 50% either had no previous climbing experience or less than one year of experience.
...
The errors observed in the rock climbing accidents fell into two categories: seven cases of obvious lack of needed protection, and four cases where a rope should have been used but was not available. In contrast to other climbing areas, little intentional free solo (unroped) climbing was attempted in the Tetons during this study”