Year	per 1000 people
1985	3.72
1986	3.816
1987	3.885
1988	3.941
1989	3.977
1990	4.027
1991	3.905
1992	3.928
1993	3.978
1994	4.091
1995	4.062
1996	4.098
1997	4.129
1998	4.125
1999	4.147
2000	4.01
2001	4.027
2006	3.95
2007	4.034
2008	3.664
2010	3.915
2011	4.041
2012	4.178
2013	4.268
2014	4.33
2015	4.379