Year	Measure
1990	0.815
1991	0.817
1992	0.82
1993	0.839
1994	0.848
1995	0.856
1996	0.859
1997	0.862
1998	0.867
1999	0.873
2000	0.877
2001	0.88
2002	0.882
2003	0.888
2004	0.89
2005	0.892
2006	0.895
2007	0.897
2008	0.898
2009	0.895
2010	0.901
2011	0.903
2012	0.904
2013	0.906
2014	0.909
2015	0.913