Bureau of Justice Statistics,
Homicide trends in the United States,
www.ojp.usdoj.gov/bjs/homicide,
Date of release: May 30 2007,

Law Enforcement Officers Feloniously Killed,

Year,Total killed*
1973,134
1974,132
1975,129
1976,111
1977,93
1978,93
1979,106
1980,104
1981,91
1982,92
1983,80
1984,72
1985,78
1986,66
1987,74
1988,78
1989,66
1990,66
1991,71
1992,64
1993,70
1994,79
1995,74
1996,61
1997,70
1998,61
1999,42
2000,51
2001,70
2002,56
2003,52
2004,57
2005,55

"* The 72 deaths that resulted from the events of September 11, 2001 are not included in this total",
"Source:  FBI,  Law Enforcement Officers Killed and Assaulted, 1973-2005",