I don't know for certain that 36 were offered - but I haven't heard anything on the contrary. I believe they just pulled off the bottom handful of facilities and replaced them with different ones. The "rule" is 25% not to exceed 5 facilities will be mandatory. This would mean 2 facilities were mandatory for this last class.
They way I read this is that the amount of mandatory locations can not exceed 25% of the students that passed. But, 25% of 18 is only 4.5 - do they round up to get to 5 mandatory locations only if everyone passes?