Year	per 1,000 people
1970	7.4
1971	8
1972	6.9
1973	7.7
1974	7.6
1975	6.9
1976	7
1977	6.5
1978	7.1
1979	6.3
1980	7.1
1981	6.7
1982	7.1
1983	8.1
1984	7.8
1985	7.5
1986	8.1
1987	8
1988	9
1989	7.9
1990	7.5
1991	8.4
1992	8.5
1993	8.2
1994	7.8
1995	8.4
1996	9.1
1997	8.6
1998	8.5
1999	9
2000	7.8
2001	7.8
2002	8.4
2003	8.5
2004	7.9
2005	8.6
2006	8.7
2007	7.9
2008	7.9
2009	7.9
2010	7.2
2011	7.9
2012	8.5
2013	7.6
2014	8.2
2015	7.8
2016	7.7
2017	9
2018	7.8
2019	8
2020	7
2021	8.1
2022	9.1