It's hard to correlate the two because there have been several policies put in place to reduce crime over the years, don't forget that our main industry is tourism and happy people spend more :-).

I can tell you that in the late 90s some areas of Lisbon were pretty dismal if not outright dangerous, and now the city seems much safer. I believe there are some studies on the effects on crime rates mentioned in one of the links above (my original comment).