Year	Percent of Total
1990-01-01	66.6412928200735
1991-01-01	66.5247969346058
1992-01-01	66.4722500448650
1993-01-01	66.4646226236923
1994-01-01	66.4748911388775
1995-01-01	66.4936691046784
1996-01-01	66.4791132997129
1997-01-01	66.3904025934561
1998-01-01	66.2475117755647
1999-01-01	66.0939290642315
2000-01-01	65.9654612882163
2001-01-01	65.9877952939092
2002-01-01	66.0780276935924
2003-01-01	66.2436287128197
2004-01-01	66.4829980915592
2005-01-01	66.7802208272481
2006-01-01	67.0730203746987
2007-01-01	67.4346216738874
2008-01-01	67.7916890853528
2009-01-01	68.0519916917786
2010-01-01	68.1678360648330
2011-01-01	68.1131310579596
2012-01-01	67.9307007805306
2013-01-01	67.6582907474764
2014-01-01	67.3482832082796
2015-01-01	67.0271870283168
2016-01-01	66.6033074745442
2017-01-01	66.1799445633471