Year	per 1,000 people
1960	1.8509316551824704
1970	1.8984034962907552
1980	1.7502481501881135
1981	1.748799694063705
1990	1.742874846106166
2000	1.6402451923550387
2001	1.6167594325481964
2002	1.6476293820395405
2003	1.6436456899537746
2004	1.6720612900593022
2005	1.6726254323864842
2006	1.7111680331166297
2007	1.674968363883509
2008	1.612710065233597
2009	1.5167164223555514
2010	1.6117793980702624
2014	1.4958400027649086
2015	1.5331177231740767
2016	1.477597151682233
2017	1.4231318837788896