Year	per 1,000 people
1960	28
1961	25.5
1962	25.8
1963	26
1964	25.3
1965	24.6
1966	24
1967	22.2
1968	21
1969	20.7
1970	19.7
1971	20.8
1972	22.4
1973	21.7
1974	19.9
1975	20.1
1976	19.5
1977	18
1978	18.6
1979	19.8
1980	19.8
1981	18.8
1982	18.5
1983	18.4
1984	17.2
1985	16
1986	16.4
1987	16.6
1988	18.7
1989	18
1990	18.7
1991	17.6
1992	17.7
1993	17.5
1994	16.7
1995	16
1996	16.1
1997	15.3
1998	15.2
1999	14.8
2000	15.3
2001	14.4
2002	14.1
2003	14.3
2004	14.5
2005	14.4
2006	14.5
2007	14.6
2008	15.2
2009	15.8
2010	15.4
2011	14.1
2012	14.1
2013	13.4
2014	13.4
2015	12.5
2016	12
2017	11.9
2018	12
2019	12.3
2020	12.3
2021	13.1
2022	11.5