Year	Percent
1986-01-01	87.7543734663963
1987-01-01	86.9470044690006
1988-01-01	84.7980986427926
1989-01-01	83.5918243345349
1990-01-01	83.2143930323441
1991-01-01	82.9889874746369
1992-01-01	82.4810168650073
1993-01-01	82.5911253474608
1994-01-01	83.1116790835362
1995-01-01	83.6574284544265
1996-01-01	83.9384834454381
1997-01-01	83.9651887519760
1998-01-01	83.3548010409770
1999-01-01	82.9879240257099
2000-01-01	83.1110071342999
2001-01-01	83.2601267432533
2002-01-01	83.8596592200229
2003-01-01	82.9513934498914
2004-01-01	83.6624844184640
2005-01-01	84.3625514740426
2006-01-01	84.9806755063744
2007-01-01	84.9050015329220
2008-01-01	84.3268757334733
2009-01-01	83.6778378732114
2010-01-01	83.2901489910974
2011-01-01	83.2691562327888
2012-01-01	82.7272155545178
2013-01-01	82.7379081466718
2014-01-01	83.8316008125509
2015-01-01	83.9258760164933
2016-01-01	84.9531425946079
2017-01-01	85.7391131967335