Year	per 1,000 people
1960	18.9
1961	17.9
1962	18
1963	17.5
1964	18
1965	17.7
1966	18
1967	18.8
1968	18.4
1969	17.6
1970	16.5
1971	16
1972	15.9
1973	15.4
1974	16.1
1975	15.7
1976	16
1977	15.4
1978	15.5
1979	15.5
1980	15.4
1981	14.5
1982	14
1983	13.5
1984	12.7
1985	11.7
1986	11.3
1987	10.6
1988	10.7
1989	10.1
1990	10
1991	9.9
1992	10
1993	9.7
1994	9.9
1995	9.6
1996	9.5
1997	9.6
1998	9.4
1999	9.4
2000	9.6
2001	9.4
2002	9.5
2003	9.6
2004	9.6
2005	9.8
2006	10.2
2007	10.1
2008	10.7
2009	10.6
2010	10.3
2011	9.6
2012	9.1
2013	8.6
2014	8.5
2015	8.5
2016	8.6
2017	8.2
2018	8.1
2019	7.8
2020	7.9
2021	8.1
2022	7.3