Year	per 1,000 people
1960	0.276
1965	0.481
1970	0.739
1971	0.911
1972	0.845
1977	1.036
1980	1.367
1983	1.415
1984	1.407
1985	1.406
1990	1.371
1991	1.452
1992	1.593
1993	1.368
1994	1.285
1995	1.292
1996	1.308
1997	1.323
1998	1.338
2000	1.359
2001	1.3
2002	1.17
2003	1.196
2004	1.208
2006	1.207
2007	1.218
2009	1.248
2010	1.249
2011	1.234
2012	1.278
2013	1.285
2016	1.219
2018	2.163
2019	1.651
2020	1.883