Year	per 1,000 people
1960	4.52356004714966
1970	5.38210010528564
1980	5.65299987792969
1981	5.72009992599487
1989	5.08640003204346
2000	4.52
2001	4.4
2002	4.4
2003	4.3
2004	4.2
2005	3.83
2006	3.8
2007	3.8
2008	3.78
2009	3.76
2010	3.57
2011	3.51
2012	3.46
2013	3.41
2014	3.42
2015	3.42
2016	3.43
2017	3.4