- b.c.,
The number of police officers killed in the line of duty has continued its 40-year decline. You can see the figures by year, up to 2014, here: http://www.nleomf.org/facts/officer-fatalities-data/year.html (National Law Enforcement Officers Memorial Fund)
The total number of deaths of police officers in the line of duty (including accidents, heart attacks, and so on--not just deaths at the hands of other people) in 2015 at this point is up from what it was at this point last year by a total of all of one percent, according to this page: https://www.odmp.org/search/year (Officer Down Memorial Page)
As was already pointed out by others and via several linked references.