Year	per 1,000 people
1960	3.6742901802063
1970	3.77640008926392
1980	3.40639996528625
1989	3.17670011520386
1990	3.1586000919
1993	3.0999999046
1996	2.6700000763
2000	2.72
2001	2.62
2002	2.54
2003	2.51
2004	2.41
2005	2.31
2006	2.33
2007	2.29
2008	2.28
2009	2.27
2010	2.04
2011	2.22
2012	2.17
2013	2.17
2014	2.12
2015	2.14
2016	2.12
2017	2.11
2018	2.06