Year	per 1,000 people
1960	10.5
1970	11.3000001907349
1980	11.5
1985	11
1990	10.3999996185
1991	10.1000003815
1992	9.8999996185
1993	9.6999998093
1994	9.6999998093
1995	9.6999998093
1996	9.6000003815
1997	9.3999996185
1998	9.3000001907
1999	9.1999998093
2000	9.12
2001	9.01
2002	8.87
2003	8.74
2004	8.58
2005	8.47
2006	8.3
2007	8.24
2008	8.21
2009	8.24
2010	8.25
2011	8.38
2012	8.34
2013	8.28
2014	8.23
2015	8.13
2016	8.06
2017	8