I'm not sure that profit is relevant here; you would have to look at revenue or (even better) head-counts of moviegoers. My understanding is that domestic (US) ticket sales peaked in 2002 at 1.58B while revenue continued to rise until 2009 due to rising ticket prices. Source:
Anyway, my original point was that if you assume aggregate leisure time has changed little over the last decade -- it's impossible to ignore competition from other entertainment activities vying for the same space -- especially when you've got absolutely meteoric growth in the gaming industry.