Postmedia reports “more than 10,000.” The Globe says the RCMP said it was between 10,000 and 12,000. The Catholic Register says Mark Warawa said that organizers said it was more than 20,000. Lifesite says organizers said it was likely near 25,000 because last year’s count was 19,500 and this year’s crowd was bigger. But, according to the Toronto Sun’s report at the time, the RCMP pegged the 2012 crowd at 10,000.
Crowd estimates—especially when there aren’t at least some chairs to count—are dicey and this can all get a bit silly, but it’s still possible, using the lower estimate of the RCMP, that there were more people on the Hill this year than in recent years.