Serious crime in Philadelphia fell last year to levels unseen in decades, according to the city police.

There were fewer violent crimes than in any other year since 1979, the fewest number of property crimes since 1971, and the fewest number of robberies since 1969.

The numbers of burglaries were the lowest on record, and although homicides decreased only slightly compared with 2015, they remained below 300 - once considered a low-end benchmark for Philadelphia - for the fourth consecutive year.

Those statistics were part of the year-end uniformed crime reporting (UCR) data provided by the department.

Commissioner Richard Ross on Wednesday described the results as a step in the right direction but said police would continue seeking to drive the numbers lower.

"We've got a long way to go," he said. "Nobody is suggesting anything other than that."

The commissioner and criminologists said the decrease was likely driven by a variety of factors, such as increased use of technology in fighting crime, continuing successful deployment and patrol strategies, and an overall crime rate that is lower across the country today than it was 20 years ago.

"It's not a simple answer, and there are probably multiple factors that are interacting with each other," said Jerry Ratcliffe, a professor of criminal justice at Temple University.

Ross also acknowledged that crime reduction was not divided equally across the city. Parts of North Philadelphia, Fairhill, and Kensington, in particular, continue to be plagued by high levels of gun violence, he said, and high levels of poverty, unemployment, and drugs can complicate efforts to reduce it.

"We're not happy with the level of gun violence across the city, period," Ross said.

Year-end statistics provided by the department showed that violent crime - which includes homicide, rape, robbery, and aggravated assault - was down about 5 percent in 2016 compared with 2015. The total number of violent crimes was 15,385, the numbers show, the lowest total since 1979, when there were 14,537.

The population of Philadelphia has shrunk during that time, meaning the violent crime rate has actually increased, from 849 violent crimes per 100,000 residents in 1979, to about 981 violent crimes per 100,000 residents in 2016.

Still, the 2016 rate - calculated using 2015's population, the most recently available data - would represent Philadelphia's lowest violent crime rate since 1984.

The 2016 homicide total, meanwhile, was 273, according to the UCR numbers; the department on its website reported 277. A police spokesman said the discrepancy was due to differences in how the department and UCR categorize certain cases.

Still, either figure was slightly lower than the 280 homicides recorded in 2015. The last time the city topped 300 homicides was 2012, when there were 331, according to police statistics. The record high in recent history was in 1990, when the city saw 500 homicides amid an epidemic of crack cocaine.

Non-fatal shooting victims is not maintained as a UCR category, but the department said in an email this week that the city had 1,280 shooting victims in 2016, the highest total since 2011, when there were 1,407.

The number of shooting incidents in 2016, however, was down significantly: 1,591, the lowest total of the last six years.

The uptick in victims - with a decrease in incidents - suggests shooters in 2016 either hit people more frequently, or hit more people at once.

Property crime last year was virtually identical to that in 2015, according to UCR figures, meaning that total "part one" crimes - the combined number of violent and property crimes - were lower than any other year since 1971.

Ross said the department would seek to continue any success - and evolve strategies as needed to improve.

"If you have something that is working, continue to improve upon it," he said. "You've got to keep moving forward." 215-854-2817 @cs_palmer