Year	per 1,000 people
1960	4.04060935974121
1970	2.90960001945496
1975	3.33330011367798
1980	2.81389999389648
1981	2.74609994888306
1999	2.6
2004	2.1
2005	2.09
2008	2.1
2009	2.1
2011	2.19
2013	2.19
2014	1.85
2015	1.87
2016	2