Year	per 1000 people
1960	1.3
1961	1.2
1962	1.3
1963	1.3
1964	1.4
1965	1.4
1966	1.4
1967	1.5
1968	1.5
1969	1.6
1970	1.6
1971	1.7
1972	1.7
1973	1.9
1974	2
1975	2
1976	2.1
1977	2.2
1978	2.3
1979	2.3
1980	2.4
1981	2.5
1982	2.6
1983	2.8
1984	2.9
1985	2.9
1986	3.1
1987	3.3
1988	3.2
1989	3.3
1990	3.4
1991	3.6
1992	3.7
1993	3.8
1994	3.8
1995	3.9
1996	3.9
1997	4
1998	4.1
1999	4.2
2000	4.3
2001	4.38
2005	5
2006	5.35
2008	6.043
2010	6.197
2011	6.226
2012	6.23
2013	6.231
2014	6.255