Year	Measure
1990	0.755
1991	0.764
1992	0.772
1993	0.783
1994	0.792
1995	0.801
1996	0.806
1997	0.81
1998	0.815
1999	0.82
2000	0.825
2001	0.828
2002	0.83
2003	0.833
2004	0.837
2005	0.844
2006	0.849
2007	0.854
2008	0.858
2009	0.86
2010	0.867
2011	0.871
2012	0.874
2013	0.877
2014	0.882
2015	0.884