Year per 1,000 people 1960 16 1961 16.1 1962 16 1963 15.8 1964 16 1965 16 1966 15.6 1967 14.8 1968 14 1969 13.3 1970 13 1971 13 1972 11.8 1973 10.8 1974 11.1 1975 11.1 1976 10.9 1977 11.2 1978 11.2 1979 11.2 1980 11.4 1981 12.1 1982 11.8 1983 11.4 1984 11.5 1985 11.2 1986 11.7 1987 11.4 1988 12.3 1989 12.4 1990 12.9 1991 12.9 1992 13.1 1993 13.5 1994 13.5 1995 13.3 1996 13.7 1997 13.1 1998 12.7 1999 13 2000 13.1 2001 12.4 2002 12 2003 11.7 2004 11.9 2005 11.5 2006 11.7 2007 11.4 2008 11.5 2009 11.3 2010 11.6 2011 10.9 2012 11.3 2013 11.3 2014 10.9 2015 10.7 2016 10.4 2017 10.4 2018 10.3 2019 10 2020 10.2 2021 10.5 2022 9.9