Year	per 1,000 people
1960	0.354
1965	0.377
1970	0.42
1977	0.478
1990	0.803
1991	0.859
1992	0.917
1993	0.958
1994	1.003
1995	1.049
1996	1.09
1997	1.133
1998	1.18
1999	1.218
2000	1.26
2001	1.285
2002	1.317
2003	1.348
2004	1.387
2005	1.429
2006	1.467
2007	1.509
2008	1.561
2009	1.616
2010	1.664
2011	1.726
2012	1.785
2013	1.853
2014	1.93
2015	1.991
2016	2.057
2017	2.131
2018	2.202
2019	2.259
2020	2.325
2021	2.362