Year	per 1,000 people
1960	4.14548826217651
1970	4.10489988327026
1975	4.99949979782104
1985	3.33330011367798
1989	2.40009999275208
1990	2.2000000477
1993	2.1003000736
1995	2.1
1996	2.1199998856
2001	1.5
2002	1.5
2003	1.3999999762
2004	1.8
2005	1.7
2006	2
2007	1.7
2009	1.7
2010	1.76
2012	1.67
2013	1.66
2015	1.69
2016	1.78
2017	1.72