Year per 1,000 people 1960 32.4 1961 31.4 1962 31.3 1963 31 1964 31 1965 30.7 1966 28.9 1967 26.7 1968 25.5 1969 24.9 1970 24.8 1971 25.6 1972 24 1973 23.3 1974 24.3 1975 23.8 1976 24.2 1977 24.5 1978 24.1 1979 23.4 1980 22.8 1981 22 1982 21.05 1983 20.1 1984 19.3 1985 19.4 1986 19.45 1987 19.5 1988 19.3 1989 19.1 1990 18.5 1991 18.1 1992 17.8 1993 17.9 1994 17.5 1995 17 1996 16.9 1997 16.2 1998 15.7 1999 15.6 2000 15.59 2001 14.59 2002 13.7 2003 13.1 2004 13.16 2005 12.96 2006 12.41 2007 11.86 2008 11.79 2009 11.72 2010 11.3 2011 11.1 2012 10.6 2013 10.1 2014 9.7 2015 9 2016 8.3 2017 7.3 2018 6.7 2019 6.4 2020 6 2021 5.9 2022 5.9