Year	per 1,000 people
1970	5.5314998626709
1981	2.93959999084473
1989	2.30029988288879
1997	1.6499999762
2000	2.36
2001	2.42
2002	2.36
2003	2.36
2004	2.36
2005	2.43
2006	2.52
2007	2.52
2008	2.52
2009	1.4
2010	1.23
2011	1.2
2012	1.2
2013	1.4
2014	1.2
2015	1.2
2016	1.2
2017	1.25