Year	Percent
1991-01-01	45.3310012817383
1992-01-01	46.1780014038086
1993-01-01	45.3810005187988
1994-01-01	45.4669990539551
1995-01-01	47.3689994812012
1996-01-01	46.0369987487793
1997-01-01	45.9700012207031
1998-01-01	45.9580001831055
1999-01-01	45.9090003967285
2000-01-01	45.8670005798340
2001-01-01	45.9059982299805
2002-01-01	47.7080001831055
2003-01-01	47.9129981994629
2004-01-01	47.5429992675781
2005-01-01	48.5219993591309
2006-01-01	47.9010009765625
2007-01-01	48.2290000915527
2008-01-01	47.4339981079102
2009-01-01	48.2849998474121
2010-01-01	47.6139984130859
2011-01-01	47.6730003356934
2012-01-01	48.2060012817383
2013-01-01	48.3889999389648
2014-01-01	48.7360000610352
2015-01-01	49.1290016174316
2016-01-01	49.4389991760254
2017-01-01	49.4449996948242