Year	Percent of Total
1990-01-01	48.5594390549117
1991-01-01	48.5904166318557
1992-01-01	48.6112939087926
1993-01-01	48.6218725934379
1994-01-01	48.6151571442394
1995-01-01	48.5829555847075
1996-01-01	48.6043439216393
1997-01-01	48.5232208591201
1998-01-01	48.3676582456126
1999-01-01	48.1444825326475
2000-01-01	47.8264876083188
2001-01-01	47.4497317718171
2002-01-01	47.0598976220824
2003-01-01	46.6193753253242
2004-01-01	46.1092778309386
2005-01-01	45.5500437619017
2006-01-01	44.9112318182154
2007-01-01	44.2650670359762
2008-01-01	43.6227094911884
2009-01-01	42.9968135293119
2010-01-01	42.3995206093003
2011-01-01	41.9082647841824
2012-01-01	41.4033425223984
2013-01-01	40.9185882259136
2014-01-01	40.4909833220384
2015-01-01	40.1316867415102
2016-01-01	39.8286682231530
2017-01-01	39.5734448833139