Year	per 1000 people
1960	1
1961	1
1962	1
1963	1
1964	1
1965	1
1966	1
1967	1
1968	1.1
1969	1.1
1970	1.1
1971	1.2
1972	1.2
1973	1.2
1974	1.2
1975	1.3
1976	1.3
1977	1.3
1978	1.5
1979	1.6
1980	1.7
1981	1.5
1982	1.7
1983	1.7
1984	1.7
1985	1.8
1986	1.9
1987	1.8
1988	1.9
1989	2
1990	2
1991	2
1992	2.1
1993	2.1
1994	2.2
1995	2.2
1996	2.3
1997	2.4
1998	2.4
1999	2.5
2000	2.5
2001	2.5
2002	2.6
2003	2.7
2004	2.73
2005	2.852
2007	2.862
2010	2.764
2011	2.748
2012	2.776
2013	2.799
2014	2.855
2015	2.92
2016	2.921