A few months ago (maybe leading up to the Christmas/New Year's party season), the Wall Street Journal ran a story on recent surveys showing that a slight majority (54%? Can't remember exactly) of drinking-age US residents either never drink, or drink only once or twice a year. The exact numbers of non-drinkers vs. occasional drinkers weren't given.

For con-goers, I can only offer the data point that my SO and I are both non-drinkers. Him because he figures being Scotch-Irish with a dash of Cherokee gives him too good a shot at alcoholism, and me because alcohol just tastes hideous to me.