Year	Percent
1991-01-01	33.0429992675781
1992-01-01	32.7770004272461
1993-01-01	33.5060005187988
1994-01-01	34.5579986572266
1995-01-01	36.3540000915527
1996-01-01	36.7719993591309
1997-01-01	36.6959991455078
1998-01-01	36.6220016479492
1999-01-01	36.5149993896484
2000-01-01	36.2659988403320
2001-01-01	35.7649993896484
2002-01-01	35.1730003356934
2003-01-01	34.9669990539551
2004-01-01	34.9599990844727
2005-01-01	34.8400001525879
2006-01-01	34.9720001220703
2007-01-01	36.5400009155273
2008-01-01	36.4690017700195
2009-01-01	37.1030006408691
2010-01-01	36.6290016174316
2011-01-01	35.8889999389648
2012-01-01	35.4119987487793
2013-01-01	34.3310012817383
2014-01-01	34.5340003967285
2015-01-01	34.0279998779297
2016-01-01	33.1809997558594
2017-01-01	33.2589988708496