Year	Percent
1991-01-01	52.0989990234375
1992-01-01	52.7500000000000
1993-01-01	52.1339988708496
1994-01-01	53.6010017395020
1995-01-01	56.4710006713867
1996-01-01	59.2939987182617
1997-01-01	59.3120002746582
1998-01-01	60.6870002746582
1999-01-01	61.7340011596680
2000-01-01	62.3979988098145
2001-01-01	62.0870018005371
2002-01-01	61.8079986572266
2003-01-01	61.3899993896484
2004-01-01	62.8279991149902
2005-01-01	63.2169990539551
2006-01-01	63.2709999084473
2007-01-01	63.9280014038086
2008-01-01	63.2360000610352
2009-01-01	61.6010017395020
2010-01-01	60.7360000610352
2011-01-01	60.3019981384277
2012-01-01	59.0079994201660
2013-01-01	59.5950012207031
2014-01-01	57.3079986572266
2015-01-01	58.2159996032715
2016-01-01	59.8600006103516
2017-01-01	59.5309982299805