I'd look at what the people who deal with the safety issue in Toronto for facts. Something like these people:My parents are refusing to let me go to Toronto because they don't feel it's a "safe" place to go and they say it's a foreign country blah blah blah. I'm going to be 20 soon so I don't think that's a problem.
So how safe of a place is Toronto actually? is it safe enough for a 19 year old girl or is it not that safe, but it's safer to go with someone?
Toronto Police Service :: To Serve and Protect
In 2008 people seemed to think it was a pretty safe cit:
Crime down in Toronto - thestar.com
I can't see any point in comparing it to other cities, though, because it really doesn't make any difference what the safety of another city is if you are in Toronto.