Year	per 1000 people
1960	1.269
1965	1.316
1970	1.185
1971	1.208
1973	1.242
1975	1.318
1976	1.332
1977	1.355
1978	1.377
1979	1.413
1980	1.476
1981	1.541
1982	1.635
1983	1.972
1984	1.724
1985	1.762
1986	1.783
1987	1.79
1988	1.805
1989	1.811
1990	1.802
1991	1.816
1992	1.866
1993	1.77
1994	1.765
1995	1.768
1996	1.81
1997	1.791
1998	1.836
1999	1.909
2000	1.889
2001	1.887
2002	1.972
2003	1.905
2006	1.917
2010	2.502
2011	2.543
2012	2.625
2013	2.669