Year	per 1,000 people
1960	0.8
1961	0.8
1962	0.9
1963	0.8
1964	0.8
1965	0.9
1966	0.9
1967	0.9
1968	1
1969	0.9
1970	0.9
1971	1
1972	1
1973	1.1
1974	1.2
1975	1.2
1976	1.3
1977	1.5
1978	1.7
1979	1.9
1990	2.8
1991	2.838
1992	2.859
1993	2.871
1994	2.89
1995	2.923
1996	3.002
1997	3.043
1998	3.099
1999	3.121
2000	3.202
2001	3.252
2002	3.285
2003	3.336
2004	3.411
2005	3.495
2006	3.565
2007	3.651
2008	3.746
2009	3.853
2010	3.979
2011	4.12
2012	4.238
2013	4.397
2014	4.561
2015	4.75
2016	4.936
2017	5.115
2018	5.294
2019	5.45
2020	5.615