Year	per 1000 people
1960	1.2
1962	1.2
1963	1.1
1964	1.2
1965	1.3
1966	1.3
1967	1.3
1968	1.4
1969	1.4
1970	1.4
1971	1.5
1972	1.5
1973	1.6
1974	1.7
1975	1.7
1976	1.8
1977	1.9
1978	1.9
1979	1.9
1980	2
1981	2
1982	2.1
1983	2.1
1984	2.2
1985	2.2
1986	2.3
1987	2.5
1991	2.6
1992	2.6
1993	2.6
1994	2.7
1995	2.8
1996	2.8
1997	2.5
1998	2.7
1999	2.8
2000	2.9
2001	3
2002	3.1
2003	3.1
2006	3.77
2007	3.889
2008	4.076
2009	4.053
2010	4.112
2011	4.187
2012	4.232
2013	4.303
2014	4.42
2015	4.385