Year	per 1000 people
1960	1.1
1961	1.1
1962	1.1
1963	1.1
1964	1.1
1965	1.2
1966	1.2
1967	1.2
1968	1.2
1969	1.2
1970	1.2
1971	1.3
1972	1.4
1973	1.4
1974	1.5
1975	1.6
1976	1.7
1977	1.7
1978	1.8
1979	1.8
1980	1.9
1981	2
1982	2
1983	2.1
1984	2.2
1985	2.2
1986	2.3
1987	2.4
1988	2.4
1989	2.4
1990	2.5
1991	2.6
1998	2.9
1999	3.1
2000	3.2
2001	3.3
2002	3.1
2003	3.149
2005	3.71
2007	3.921
2014	3.424
2015	3.478