Year	Percent
1991-01-01	42.1573262195436
1992-01-01	41.9833632491954
1993-01-01	41.7744603484034
1994-01-01	41.6736663542899
1995-01-01	41.2403443377108
1996-01-01	41.5372407693154
1997-01-01	41.5088543339196
1998-01-01	41.0954550550618
1999-01-01	41.5250929243450
2000-01-01	41.2557073868224
2001-01-01	41.0559375091280
2002-01-01	41.0108442433210
2003-01-01	41.4244280243472
2004-01-01	42.1675148937154
2005-01-01	42.3772056684661
2006-01-01	42.7737191903170
2007-01-01	43.2043777173496
2008-01-01	43.1781045954074
2009-01-01	43.2956394214699
2010-01-01	43.0211684428823
2011-01-01	42.9397384506470
2012-01-01	42.9292977840144
2013-01-01	43.2749438247446
2014-01-01	42.9544803491667
2015-01-01	43.1082070184890
2016-01-01	43.3514166175639
2017-01-01	43.3903465117522