That's the rate of officers in the line of duty dying as part of the total number of officers. If there are say, 100 deaths a year and 100,000 officers, the per capita rate of death in the line of duty is 1 in 1000.
If there are 100 deaths a year and 1,000,000 cops, the per capita rate of death would be 1 in 10,000.
Pretty big difference. We have MORE cops now than we did 30 years ago, but numbers of deaths of police in the line of duty near a 30 year low. That means that the risk to an individual officer today is lower than it was 30 years ago.
Which just kicks the shit out of any 'war on cops' horseshit.
And can I back up that we have more cops now than we did 30 years ago? Would you accept the
"Highest figure ever' about covers it, yes?
And while this report caps out at 2008, it demonstrates a pretty clear direction in terms of the total number of officers:
http://www.bjs.gov/content/pub/pdf/hrslleo08st.pdf