You can't go over 25. Think February to February. 25 per calendar year.
For simplicity:
We sign 18 on February signing day.
December early signing 20 kids and 7 are early enrollees. Since the early enrollees are in before February you can count those back to the previous signing day.
18 + 7 early enrollees = previous years cap
20 -7 = 13 for the current year meaning we could take a combo of 12 more signees/transfers/etc. To hit the next cap.
On paper it would look like we took a class of 32 but 7 are back counted.
Or save some for early enrollees again. Rinse and repeat.
Kids leaving does not free up extra spots.