Year	Percent
1986-01-01	44.3692543009277
1987-01-01	45.1514713934350
1988-01-01	46.8363979326977
1989-01-01	48.4592446271490
1990-01-01	48.5849304566008
1991-01-01	48.4091679927721
1992-01-01	49.6814012066731
1993-01-01	51.5537126221448
1994-01-01	51.0969976797306
1995-01-01	50.8187221928403
1996-01-01	50.7877352319893
1997-01-01	50.8881784970412
1998-01-01	51.0231735767699
1999-01-01	49.2191736599191
2000-01-01	49.1262265534061
2001-01-01	48.5500594207965
2002-01-01	48.4277514747084
2003-01-01	49.2527880478921
2004-01-01	49.5274235066970
2005-01-01	50.4175377942149
2006-01-01	50.4911314706236
2007-01-01	51.0200961080016
2008-01-01	51.6715105974796
2009-01-01	50.4542860887806
2010-01-01	53.7047059047174
2011-01-01	55.5424811765902
2012-01-01	55.7162174525843
2013-01-01	56.0175148466134
2014-01-01	55.9767646344269
2015-01-01	55.9563196863238
2016-01-01	55.6027599629680
2017-01-01	55.7188495394018