January 9 is National Law Enforcement Appreciation Day. The day of recognition was created in 2015 to thank officers across the country for dedicating their lives to improving their communities. There are about 18,000 police departments in the U.S., with more than 900,000 active officers. About 12 percent of those are women. Last year, 128 police officers were killed in the line of duty. During the past decade, 1,512 officers have been killed while on the job, an average of 151 deaths per year.