About as many go to the movies on Christmas Day? Remember, some of us are Jewish. Some are Hindu. Some are atheists. And so on.
Not everyone celebrates/observes Christmas, and to lots of people this is just another Tuesday, albeit one on which they don't have to work and can't find an open grocery store when they run out of milk.
I agree with lv-lover, I think there'd be more of us today. After all, not everyone celebrates, and there's really nothing to do regardless. It'll be interesting to see the numbers either way.