Year	per 1000 people
1960	1.2
1961	1.2
1962	1.2
1963	1.2
1964	1.2
1965	1.2
1966	1.2
1967	1.2
1968	1.3
1969	1.3
1970	1.4
1971	1.5
1972	1.6
1973	1.6
1974	1.7
1975	1.8
1976	1.9
1977	1.9
1978	2
1979	2
1980	2.1
1981	2.2
1982	2.3
1983	2.3
1984	2.4
1985	2.6
1986	2.6
1987	2.7
1988	2.7
1989	2.8
1990	2.8
1991	2.8
1992	3
1993	3
1994	3
1995	3
1996	3.1
1997	3.3
1998	3.3
1999	3.4
2000	3.442
2001	3.485
2002	3.587
2003	3.613
2004	3.603
2005	3.606
2006	3.633
2007	3.69
2008	3.735
2009	3.713
2010	3.591
2011	3.483
2012	3.531
2013	3.59
2014	3.645
2015	3.791