It's not so simple to count homicides in the Big Apple.

A last-minute end-of-the-year statistical adjustment has boosted the number of homicides in 2014 from 327 to 332, still a record-low for the modern era of police record keeping, according to the NYPD.

The increase was chalked up to five so-called reclassifications of incidents that occurred earlier -- sometimes four decades ago -- and that investigators and medical experts decided led to deaths in 2014, officials said. Adding all reclassifications to the 316 actual homicides that occurred in the previous 12 months, the year 2014 ended with 332 killings in New York City, a shade below last year's record of 335.

However, the 2014 homicide number is still not etched in stone. A police spokeswoman said one of the latest reclassified killings might revert to a noncriminal finding.

Since police record keeping on homicides became consistent from only about 1962, NYPD officials are only comfortable making comparisons as far back as that year, in which 508 homicides were tallied. Homicides dipped under 300 in some years of the 20th century but those figures aren't easily compared to modern police statistical methods, according to experts.

Still, even at 332 homicides, New York City has a killing rate of 3.95 per 100,000 population, the first time it has been under 4.0 since the 1950s.

Through late Friday, 2015 recorded two known homicides, one in the Bronx and another in Queens, with a third Queens incident of death under investigation by the city medical examiner, an NYPD spokeswoman said.

NYPD Commissioner William Bratton is expected to go into detail about 2014 crime trends early next week at a news conference, according to law enforcement officials. The city recorded a 4.8 percent drop in serious crimes last year over 2013.