This Post article doesn't provide a source. Mine claims the NYPD as a source but doesn't link it either, though. It seems like only one of these can be correct: there would have to be a very large spike in felony assaults in a single month for the number to go up by 9% YoY.

The Times article doesn't mention this year's stats. Last year's were definitely worse, so it's not surprising they mention that.