Year	per 1,000 people
1960	0.441
1970	0.35
1980	0.361
1981	0.404
1986	0.28
1989	0.207
1992	0.365
1996	0.344
1998	0.33
1999	0.659
2003	0.267
2005	0.265
2008	0.443
2010	0.329
2013	0.46
2016	0.326
2020	0.554