The numbers make more sense if you think of it terms of copies of games instead of number of people. Naturally, pirates will play tons of games -- it's not like it costs them anything to download ten games a month. Paying gamers probably buy only one or two games a month, if that.
Thats apples and oranges isen't it. Only a very small percentage of pirated copies translate into potential sales.
I have done a fair ammount of pirating in my day, I don't get much time to play at all these days so I don't bother, if something is worth my interest the cost wont kill me, and I prefer to have it in working order able to receive patches and updates, but there was a time where abject poverty prevented me from getting any games at all, other than the free way.