Year	per 1,000 people
1960	1.00650095939636
1970	1.04260003566742
1975	0.9932000041008
1980	0.890699982643127
1981	0.870199978351593
1990	1.0880000591
2000	0.81
2001	0.74
2002	0.73
2003	0.73
2004	0.71
2005	0.72
2006	0.73
2007	0.73
2008	0.73
2009	0.73
2010	0.72
2011	0.84
2012	0.82
2013	0.82
2015	0.67
2017	0.74