I think the key word is "need". I have been told that women get all the benefits, while men spend their precious energy and some valuable substance.
I am not being sarcastic, by the way. To answer the question, I don't know and nobody who did not do proper research does. What I know that some men have problems with performance, but I cannot give the number 25%, 35%... Whether they still need or want sex, I don't know either.
The best movie I watched on this topic was "Kinsey". If you have not had the chance, I strongly recommend. It is very enlightening.
By the way, how much does it matter if your lover is good or not?