Year	Measure
1990	0.36
1991	0.368
1992	0.378
1993	0.389
1994	0.39
1995	0.398
1996	0.406
1997	0.409
1998	0.411
1999	0.418
2000	0.422
2001	0.428
2002	0.433
2003	0.439
2004	0.446
2005	0.454
2006	0.461
2007	0.469
2008	0.477
2009	0.485
2010	0.494
2011	0.501
2012	0.506
2013	0.511
2014	0.515
2015	0.516