IOW, your stats are no better than anybody else's -- it's just an extrapolation from a single point. It may well be more than 11 million illegals, but I suspect your number is at least partly informed by a personal desire that it be more than the gov't says it is.
I will agree that nobody knows the real number. I'd rather not get hung up on just exactly how big a number it is, we can agree I hope that it is a big bumber.