Year	Measure
2000	0.604
2001	0.608
2002	0.612
2003	0.616
2004	0.617
2005	0.622
2006	0.625
2007	0.628
2008	0.629
2009	0.633
2010	0.638
2011	0.64
2012	0.641
2013	0.639
2014	0.637
2015	0.638