Year	Measure
1990	0.799
1991	0.803
1992	0.808
1993	0.815
1994	0.823
1995	0.83
1996	0.836
1997	0.842
1998	0.848
1999	0.86
2000	0.862
2001	0.875
2002	0.882
2003	0.893
2004	0.897
2005	0.902
2006	0.904
2007	0.906
2008	0.906
2009	0.906
2010	0.91
2011	0.922
2012	0.924
2013	0.926
2014	0.923
2015	0.925