If you ever want to see an example of dueling statistics, try to get a handle on how often guns are used for self-defense.

Representing opposite sides and presenting starkly different conclusions are the Violence Policy Center and the National Rifle Association.

The Violence Policy Center has issued annual reports in recent years on justifiable homicides by non-police officers involving guns. It also offers estimates of how often guns are used for self-protection.

VPC’s 2017 report on justifiable homicides involving guns reports 224 justifiable homicides involving a private citizen in 2014, the most recent year for which it has data. It bases that number on reports to the FBI’s Uniform Crime Reporting program’s Supplementary Homicide Report.

The VPC, citing statistics from the Bureau of Justice Statistics, national Crime Victimization Survey, 2013-15, also reports on self-protective behavior in the face of violent personal crime.

During that three-year period, it states, there were about 16.5 million violent personal crimes, and in about 176,000 cases – 1.1 percent – the victim “threatened or attacked with a firearm.”

Another 1.8 percent of victims threatened or attacked with another weapon, VPC reports.

The National Rifle Association states the VPC undercounts defensive homicides by using unreliable data, namely “data reported by the FBI, which reflect only law enforcement agency reports and not the final disposition of cases by the criminal justice system.”

It cites the work of criminologist Gary Kleck that, “for a variety of reasons, the FBI counts of civilian justifiable homicides represent only a minority of all civilian legal defensive homicides.”

The NRA also states “the value of guns for self-defense isn’t measured in the number of criminals killed, but in the number of violent crime victimizations prevented.”

It cites a study of people convicted of crimes and serving time in prison that “found that 40 percent had decided not to commit crimes for fear their prospective victims were armed.”

And for those wondering how many guns there are in the United States, a 2016 Harvard University-Northeastern University study indicated Americans owned an estimated 265 million guns.

Fifty-five million people owned the guns. What’s more, half of all guns were owned by so-called “super owners” with 17 or more guns each, the study found. People with 17 or more guns accounted for 3 percent of US gun owners.

USA Today based its report on summaries of the Harvard-Northeastern study that had been released to the British newspaper The Guardian and to a firearms-news website called The Trace. The study was under peer review at the time of the news reports.

The Violence Policy Center’s website states it “works to stop gun death and injury through research, education, advocacy, and collaboration.” It was founded in 1988 by Josh Sugarmann, its executive director. He is a former communications director for the National Coalition to Ban Handguns.

The National Rifle Association, begun in 1871, describes itself as “widely recognized today as a major political force and as America’s foremost defender of Second Amendment rights.” It also says that “since its inception, [the NRA has] been the premier firearms education organization in the world.”