Year	per 1,000 people
1961	1.1
1966	1.1
1971	1.1
1973	1.2
1976	1.3
1977	1.4
1978	1.4
1979	1.5
1980	1.6
1981	1.6
1982	1.6
1983	1.7
1984	1.7
1985	1.7
1986	1.8
1987	1.8
1988	1.9
1989	1.9
1990	1.866
1991	1.889
1992	1.903
1993	1.923
1994	1.983
1995	2.05
1996	2.048
1997	2.178
1998	2.229
1999	2.248
2000	2.235
2001	2.183
2002	2.126
2003	2.179
2004	2.192
2005	2.107
2006	2.274
2007	2.299
2008	2.464
2009	2.581
2010	2.626
2011	2.655
2012	2.714
2013	2.824
2014	2.894
2015	3.046
2016	3.147
2017	3.299
2018	3.353
2019	3.39
2020	3.448
2021	3.516