75 trainees > 33 graduates > 3 'MIA' + 1 WIA stated in Ghosts of Onyx and messages to the universe thingy >29 Spartans left during REACH events > 3 in space, 26 on the ground > Outcome events of reach and first strike > 5 spartans > Fred, Will, Linda, Kelly join Kurt on Onxy > John goes to Delta halo and we all know the rest.
I think that about sums it up. Too bad not all the information is as coherent as it should be, even in Fall of Reach alone, several of the dates in the book were messed up.