^^^
Well, that made me curious. While statistics often don't tell the whole picture, here's some data for the northeast US and eastern Canada (generally east of the St. Lawrence).
* The number of possible encounters reported before the P-G film is likely low due to both a lack of human witnesses and a lack of places where a report could be made without the human being locked up as a lunatic.
* The higher levels in the 70s, 80s, and 90s would have been driven primarily by "big" encounter reports (the P-G film, Fouke monster, etc.).
* The really big spike in the 2000s is due to? Not [Edit to use complete sentences] sure - this would be before Finding Bigfoot, IIRC.