While I believe even 1 LODD is too many, I found the historical data of gun related Police Officer LODD to be interesting, and definately on the down swing over the last 40 years, in actual numbers.
2008 - 2009 is the exception to this.
I found what I consider to be an exceptional (considering the subject matter) website honoring Police Officers killed in the line of duty
http://www.odmp.org/.
From this website I compiled the following numbers over the last 50 years.
These are gunshot (non-accidental) only:
1960 47 1970 107 1980 104 1990 61 2000 50
1961 56 1971 140 1981 93 1991 73 2001 65
1962 60 1972 120 1982 90 1992 65 2002 57
1963 60 1973 142 1983 81 1993 77 2003 47
1964 62 1974 140 1984 72 1994 82 2004 55
1965 63 1975 143 1985 76 1995 70 2005 53
1966 63 1976 105 1986 75 1996 60 2006 51
1967 85 1977 96 1987 75 1997 68 2007 65
1968 76 1978 100 1988 80 1998 64 2008 39
1969 100 1979 111 1989 69 1999 44 2009 48
During this 50 year period, numbers spiked around '67. They then grew rapidly through the '70s. The last year over 100 was 1980, with a fairly steady decline since.
2008 was the only time in the last 50 years below 40.
This is actual numbers. I could not find statistics on the number of Officers employed each year. If one factors the steady increase in the number of Officers employed each year, then the overall downturn (measured in deaths per-xxx) is even more pronounced.
Personally, I would like to see this number at ZERO.
Up until 2008 things were looking very promising. My hope is 2009 will be an anomoly, and we will once again see these numbers decrease.