Based on my interactions on CC (reading and posting), that 11% for Notre Dame does seem off. I would guess it’s more accurate to say half of that figure.
If we’re talking about merit aid to all students, here’s my understanding from the most recent CDS:
Merit aid was awarded to 388 full time undergraduates (excluding athletes; including freshmen) “who had no financial need.” There were 8,509 full time undergraduates (including freshmen). This seems to calculate to 4.5% if I’m doing my math correctly. (BIG disclaimer: I’m very far from a math person)