Year	per 1,000 people
1960	0.42
1965	0.526
1970	0.657
1975	0.667
1980	0.851
1981	0.877
1985	0.998
1986	0.723
1988	1.111
1990	1.266
1991	1.32
1992	1.348
1993	1.385
1994	1.411
1998	1.627
1999	1.343
2000	1.376
2001	1.437
2002	1.443
2003	1.489
2004	1.52
2005	1.553
2006	1.545
2007	1.583
2008	1.621
2009	1.661
2010	1.749
2011	1.826
2012	1.9
2013	1.999
2014	2.106
2015	2.205
2016	2.27
2017	2.322
2018	2.368
2019	2.434