Year	per 1,000 people
1960	0.356
1965	0.478
1970	0.613
1975	0.597
1981	0.993
1984	1.021
1985	1.006
1988	1.793
1990	1.122
1991	1.132
1992	1.154
1993	1.188
1994	1.135
1995	1.177
1996	1.216
1997	1.214
1998	1.204
1999	1.244
2001	1.256
2002	1.347
2003	1.352
2004	1.332
2005	1.358
2006	1.358
2007	1.312
2008	1.389
2009	1.317
2010	1.413
2011	1.505
2012	1.605
2013	1.588
2015	1.581
2016	1.574
2017	1.59
2018	1.61
2019	1.638
2020	1.629