Year	per 1,000 people
1960	0.8
1961	0.9
1962	0.9
1963	0.9
1964	0.9
1965	0.9
1966	0.9
1967	0.9
1968	0.9
1969	0.9
1970	0.9
1971	1
1972	1
1973	1.1
1974	1.1
1975	1.1
1976	1.2
1977	1.2
1978	1.2
1979	1.3
1990	1.618
1991	1.633
1992	1.646
1993	1.684
1994	1.698
1995	1.757
1996	1.798
1997	1.855
1998	1.899
1999	1.913
2000	1.994
2001	2.043
2002	2.114
2003	2.201
2004	2.331
2005	2.408
2006	2.46
2007	2.492
2008	2.571
2009	2.653
2010	2.656
2011	2.691
2012	2.697
2013	2.706
2014	2.742
2015	2.773
2016	2.783
2017	2.814
2018	2.834
2019	2.942
2020	3.041
2021	3.171