Year	per 1,000 people
1960	2.32869076728821
1970	2.63940000534058
1975	2.50149989128113
1990	1.8812999725
1993	2
1996	1.5
2003	2.0999999046
2005	2
2007	1.22
2008	1.57
2009	1.44
2010	1.59
2011	1.74
2012	1.74
2013	1.79
2014	1.79
2015	1.58
2016	1.44
2017	1.56