The male prostate is NOT the "G-Spot" as in the Gräfenberg spot which is a small area in the genital area of women behind the pubic bone and surrounding the urethra. And the G-spot is now thought to be a part of the Skene's glands, a homologue of the prostate. If any of the ladies want to clarify this a bit, feel free to do so.
So basically the question is how many women massage/stimulate their man's prostate to give him an orgasam.