A recent report showed that 1 in 10 people in any given movie theater in Missouri will be carrying a concealed handgun. That means that approximately one person on every single row of the theater has a handgun.
I come from the great state of Texas, and I suspect that this statistic would be closer to 1 in 2 people carrying a handgun in any give movie theater in Texas. It's so prevalent that we even have disclaimers at the beginning of the movie that said, "Be courteous to your fellow patrons. Please silence all cell phones and put all handguns on safety."