Year	Measure
1990	0.775
1991	0.787
1992	0.8
1993	0.813
1994	0.826
1995	0.839
1996	0.843
1997	0.849
1998	0.854
1999	0.86
2000	0.866
2001	0.87
2002	0.874
2003	0.878
2004	0.886
2005	0.89
2006	0.889
2007	0.892
2008	0.895
2009	0.895
2010	0.902
2011	0.898
2012	0.899
2013	0.904
2014	0.908
2015	0.91