Where can I find historic rates of meteor impact events? I have a friend that watches a lot of TV news and they have the impression that impact events are becoming more common than in recent memory. Does the evidence support or refute this?

Thinking it would answer the question, I've tried to find data on the annual rate of impact events. But maybe there is another way to look at it.
The database of the meteoritical society might be what you are looking for. You can do a search by year. 
Based on this data, I drew this quick plot of number of recorded meteorites per year



Now there are a couple things to see here. First is that we find as roughly as many meteorites as we did ten or twenty years ago. So these events are not more common now than they were in recent memory. This answers your friends' question. Second is that we have many more records of meteorites than we did 100 years ago. This is simply because these numbers are not the exact number of meteorites that occurred, but rather the number of meteorites that were recorded. 

The International Meteor Organization also has some databases you can browse to find more information.