Closer to 275-300 that graduate (e.g. 286 graduated in 2012).
OP since your question is in order of entering class, here is the data for the 10 largest entering classes of 2012-2013:
1. LECOM - 384 (Erie and Seton Hill - all pathways)
2. VCOM - 348 (Virginia and Carolinas campuses)
3. Western - 334 (COMP and COMP-NW)
4. NYCOM - 328
5. MSU-COM - 321 (all campuses)
6. PCOM - 277
7. KCUMB - 259
8. AZCOM - 256
9. NSU-COM - 254
10. TCOM - 239
Now for both Western and VCOM, you have to declare a campus preference when you apply, and then you are pooled into a different set of apps, so really you are applying for less seats then their starting class. If we remove those exceptions, the 10 largest entering classes are:
1. LECOM - 384 (Erie and Seton Hill - all pathways)
2. NYCOM - 328
3. MSU-COM - 321 (all campuses)
4. PCOM - 277
5. KCUMB - 259
6. AZCOM - 256
7. NSU-COM - 254
8. TCOM - 239
9. LMU-DCOM - 234
10. DMU - 224