I respectfully suggest that "acceptance rate" is a misnomer. With the exception of the UC Coast Guard Academy, there are 4 distinct courses that each must be run (and "passed") to be offered an appointment at a Fed Service Academy:
1. DOD Physical Examination (I believe a fail here for USMMA = Not Physically Qualified)
2. PFA (I believe a fail here for USMMA = Incomplete Application)
3. Congressional Nomination
4. Service Academy Application which, as I recall, has 3 separate parts (I believe a fail here for USMMA = Not Academically Qualified)
One can see that for 2018, if there were 2,217 Applications and 1,272 were incomplete, then there had to have been 945 completed applications. With 1696 nominations, there must have been applicants nominated who had incomplete applications. Likewise, one can assume some of the 945 did not get a nomination.
As Jasper indicated, the subsets are not unique. When folks ask me, I keep the answer simple (for '18). 2217 applied. 252 got in.