As he exited his office in City Hall for the final time, Rudy Giuliani was leaving on a high note. Not only was he “America’s Mayor” in the wake of the 9/11 attacks, but New York City witnessed 649 murders on its streets in 2001, a number that seems paltry if you turned back the clock to 1990, when 2,245 New Yorkers were slain.

But almost 20 years after Giuliani left office, it’s now clear that he didn’t have irreplaceable crime-fighting powers. Despite the naysayers, the numbers continued to get even better for Michael Bloomberg and then Bill de Blasio. There were 318 murders in New York City last year – that’s 50% lower than Giuliani’s safest year in 1998.

So it was an eyebrow-raising moment last week when Giuliani and Pat Lynch, the head of the police union, decided to channel Charles Bronson during the Republican National Convention last week and run against their hometown.

“New Yorkers wonder, how did we get overwhelmed by crime so quickly and to decline so fast? Don’t let Democrats do to America what they have done to New York,’’ Giuliani warned.

And indeed, New York is having a disturbing surge in crime this year – but we’re still on pace to have a year that would be far safer than any of the eight in Giuliani’s books, with about 430 estimated homicides.

Contrast that to when Pat Lynch joined the NYPD in 1984 and 1,450 city residents were murdered. No one then was likely standing at the Democratic National Convention blaming Ronald Reagan for anarchy on our streets.

We should all be concerned about the recent rise in crime, but we should also recognize fear-mongering for what it is when it heads our way. In an era where “people tell me” and “I hear” are the buzzwords of the day, it’s more important than ever to look at the actual numbers before moving out of town.