Year	per 1,000 people
1960	22.5
1961	22.2
1962	20.9
1963	19.7
1964	19
1965	18.1
1966	18
1967	17.7
1968	17.6
1969	17.5
1970	17.7
1971	17.6
1972	17
1973	16
1974	15.9
1975	15.7
1976	15.7
1977	15.5
1978	15.3
1979	15.3
1980	15.2
1981	15.2
1982	15.4
1983	16.5
1984	16.4
1985	16.5
1986	16.7
1987	16.4
1988	15.5
1989	15.1
1990	15.4
1991	15.1
1992	14.7
1993	12.9
1994	11.6
1995	11.4
1996	10.8
1997	10.6
1998	10.4
1999	10.3
2000	9.8
2001	9
2002	8.6
2003	8.8
2004	8.8
2005	8.9
2006	9.1
2007	9.3
2008	9.9
2009	10.2
2010	9.9
2011	10
2012	10.2
2013	10.1
2014	10.4
2015	10.8
2016	10.7
2017	10.1
2018	10
2019	9.8
2020	9
2021	8.3
2022	7.8