Year per 1,000 people 1960 41.93 1961 40.983 1962 39.657 1963 38.083 1964 36.448 1965 34.947 1966 33.429 1967 32.015 1968 30.454 1969 30.361 1970 31.2 1971 31.2 1972 28.4 1973 28.3 1974 26.6 1975 24.8 1976 22.2 1977 22.7 1978 20.3 1979 23 1980 22.6 1981 22.4 1982 21.6 1983 19.3 1984 16.7 1985 16.1 1986 15.4 1987 15 1988 15.1 1989 15.1 1990 15.2 1991 16.4 1992 16.7 1993 16 1994 16 1995 15.7 1996 15 1997 14.5 1998 13.7 1999 13.2 2000 13.5 2001 11.7 2002 10.3 2003 10.2 2004 9.8 2005 9 2006 9.2 2007 10.1 2008 9.4 2009 9 2010 9.4 2011 9.4 2012 9.6 2013 8.6 2014 8.6 2015 8.6 2016 7.9 2017 7 2018 6.4 2019 5.9 2020 5.3 2021 5.1 2022 4.9