Year	Measure
1990	0.345
1991	0.351
1992	0.355
1993	0.361
1994	0.365
1995	0.371
1996	0.375
1997	0.38
1998	0.384
1999	0.389
2000	0.395
2001	0.407
2002	0.416
2003	0.423
2004	0.43
2005	0.434
2006	0.438
2007	0.444
2008	0.448
2009	0.451
2010	0.454
2011	0.458
2012	0.466
2013	0.475
2014	0.481
2015	0.485