Year	per 1,000 people
1960	0.495
1970	0.471
1975	0.476
1980	0.448
1982	0.494
1989	0.358
1992	0.472
1994	0.376
1997	0.476
1998	0.357
1999	0.329
2003	0.443
2008	0.376
2009	0.413
2013	0.773
2015	0.814