Year	per 1000 people
1960	1
1961	1
1962	1
1963	1
1964	1.1
1965	1.1
1966	1.1
1967	1.2
1968	1.2
1969	1.3
1970	1.3
1971	1.4
1972	1.5
1973	1.5
1974	1.6
1975	1.7
1976	1.8
1977	1.9
1978	2
1979	2
1980	2.2
1981	2.3
1982	2.3
1983	2.4
1984	2.6
1985	2.6
1986	2.8
1987	2.8
1988	2.8
1989	2.8
1990	2.9
1992	2.7
1993	2.7
1994	2.8
1995	2.9
1996	2.9
1997	2.9
1998	3
1999	3
2000	3.1
2001	3.2
2002	3.284
2004	3.28
2006	3.583
2007	3.244
2008	3.77
2009	3.868
2010	3.893
2011	3.963
2012	4.038
2013	4.119
2014	4.188