I read that number as total official Covid deaths.
Given that the risk ratio seems to hover around 1:14 (14 unvaccinated deaths per breakthrough death), my guess is that numbers would land somewhere around 1,400 breakthrough deaths and 19,600 unvaccinated deaths. Definitely not worth splitting hairs about; it’s not a line of argument that makes the Texas governor look good.
As has been pointed out up-thread, there are plenty of reasons to believe the 21,000 figure is low; Texas has an unconventional way of counting official Covid deaths.
