Angry public protests over police killings of black men and this year's ambush attacks of police in Baton Rouge and Dallas have provoked feelings that law enforcement is under siege.

However, being a police officer in Minnesota is actually safer now than it was in the 1980s, although the situation may have worsened again in recent years, according to a Star Tribune analysis of law enforcement data.

Assaults on police officers in Minnesota have been rising recently, according to numbers from the state Bureau of Criminal Apprehension. This analysis includes all assaults, whether or not it resulted in an injury or death, or whether a weapon was involved.

But the sheer increase in assaults doesn't tell the story. To measure the likelihood of an officer being attacked on the job, look at the per capita rate of attacks. After all, Minnesota's population has grown and there are more officers than in the past.

The assault rate on Minnesota officers has declined long term, although it is up from lows in the 1990s and early 2000's. The rate bumped up to five in 2014 due to a significant and unusual drop in the number of active officers that year, not because assaults spiked.

The background to the declines from the 1980s is that the state's violent crime rate – violent crimes per 100,000 people – has been falling, dropping from a peak of 359 in 1994 to 232 last year.

Likewise, the rate of officers being feloniously killed in Minnesota has drifted down. Caveat: there are very few officer fatalities in Minnesota to begin with. Many years there are none.

As for the raw increase in the number of assaults on Minnesota officers, local law enforcement say it's fueled by a number of things including a lack of respect for police authority, and drug and alcohol use.

Dennis Flaherty, head of the Minnesota Police and Peace Officers Association, said he's not focused on long term trends. It's the "now and today" that worries him, he said. Flaherty said he thinks attacks on law enforcement have become more severe, and pointed to the vicious late-night attack last November on Brooklyn Park Police officer Sean Hyman. Hyman fought for his life with a man whom he tried to arrest on an outstanding felony warrant.

"Let's face it, many people are becoming emboldened by the media attacks on police," he said.

The numbers don't necessarily bear that out. Although this year's totals aren't in yet, assaults severe enough to cause injury have declined since 2013.

A national comparison on officer assaults is nearly impossible because the FBI's Uniform Crime Report count of officer assaults is incomplete. It's a voluntary reporting program and too many large law enforcement agencies just don't report the assaults, said Robert Kaminski, associate professor at the University of South Carolina's Department of Criminology and Criminal Justice.

But the data on officer fatalities the FBI collects are very good, Kaminski said. Those data show that law enforcement fatalities have been declining for decades, dropping from about 80 per year in the 1980s down to about 50 per year more recently.

Even without a full tally for 2016, it's already clear that this year will be higher than most recent years (except 2011) due to the horrific ambush attacks in Dallas and elsewhere. There have been at least 52 deaths so far this year.

Kaminski says policing seems to be safer. "You might see short temporary increases in the number of fatalities because we're dealing with small numbers. … They're rare events. You have to look at the overall trends," he said.

The overall per capita rate of fatalities also appears to be down. Using the best available count of sworn police officers in the U.S. (a Bureau of Justice Statistics survey done every four years), the rate of fatalities has fallen from 11 per 100,000 officers in 1992 to five in 2008. The Star Tribune asked the Bureau of Justice Statistics for data from their 2014 survey, but the bureau said it is not yet available.

Data Drop is a weekly feature that uses data analysis and visualizations to explain, surprise, inform and entertain readers on topics relevant to Minnesotans. Do you have an idea you'd like us to explore? Contact MaryJo Webster