Year	per 1,000 people
1960	1.2
1961	1.2
1962	1.2
1963	1.2
1964	1.2
1965	1.2
1966	1.2
1967	1.2
1968	1.3
1969	1.3
1970	1.4
1971	1.5
1972	1.6
1973	1.6
1974	1.7
1975	1.8
1976	1.9
1977	1.9
1978	2
1979	2
1980	2.1
1981	2.2
1982	2.3
1983	2.3
1984	2.4
1985	2.6
1986	2.6
1987	2.7
1988	2.7
1989	2.8
1990	2.847
1991	2.845
1992	2.951
1993	2.952
1994	2.994
1995	3.022
1996	3.118
1997	3.257
1998	3.314
1999	3.379
2000	3.439
2001	3.471
2002	3.575
2003	3.613
2004	3.612
2005	3.609
2006	3.601
2007	3.61
2008	3.639
2009	3.645
2010	3.588
2011	3.501
2012	3.558
2013	3.605
2014	3.642
2015	3.772
2016	3.849
2017	3.871
2018	3.891
2019	3.891