Year	per 1,000 people
1990	10.9
1991	11.01
1992	10.62
1993	10.69
1994	10.36
1995	10.01
1996	9.75
1997	9.325
1998	8.924
1999	8.828
2000	8.59
2001	8.463
2002	8.258
2003	8.193
2004	8.089
2005	8.13
2006	8.132
2007	8.091
2008	8
2009	7.934
2010	7.188
2011	6.801
2012	6.642
2013	6.484
2014	6.278