At this point it appears it is 20.5% or approx. 1 out of 5. Two multiple posts not counted. Also, only one yes or no per person would make sense, as owning several BX's would be seen as a singular experience.
Total hours and conditions tractor worked would be variables which could increase or decrease risk but that would be too many variables.
I do think, in reality it is lower than the current total, but a couple of years ago there was a thread questioning the fans which seemed significant enough and the BX has been around long enough that Kubota should have addressed and simplified this repair for owners by now.