Year	per 1,000 people
1960	10
1961	9.8
1962	10.2
1963	10.1
1964	10
1965	10.1
1966	10
1967	10.1
1968	10.4
1969	10.5
1970	9.9
1971	10.2
1972	10.3
1973	10.5
1974	10.6
1975	10.8
1976	11
1977	10.7
1978	10.8
1979	11
1980	11
1981	11.1
1982	10.9
1983	10.9
1984	10.9
1985	11.3
1986	11.1
1987	11.1
1988	11.5
1989	10.8
1990	11.1
1991	11
1992	10.9
1993	11.1
1994	10.5
1995	10.6
1996	10.6
1997	10.6
1998	10.5
1999	10.7
2000	10.5
2001	10.5
2002	10.6
2003	10.4
2004	10.1
2005	10.2
2006	10
2007	10
2008	9.9
2009	9.7
2010	9.6
2011	9.5
2012	9.7
2013	9.4
2014	9.2
2015	9.3
2016	9.2
2017	9.1
2018	9.1
2019	8.6
2020	9.5
2021	8.8
2022	9