Year	Percent
1991-01-01	60.1769981384277
1992-01-01	60.2929992675781
1993-01-01	60.3050003051758
1994-01-01	60.3790016174316
1995-01-01	60.5209999084473
1996-01-01	60.5779991149902
1997-01-01	60.7589988708496
1998-01-01	60.9650001525879
1999-01-01	61.0950012207031
2000-01-01	61.4609985351563
2001-01-01	61.6629981994629
2002-01-01	60.6679992675781
2003-01-01	60.6290016174316
2004-01-01	60.9620018005371
2005-01-01	63.2789993286133
2006-01-01	65.4660034179688
2007-01-01	64.0680007934570
2008-01-01	62.9070014953613
2009-01-01	61.7430000305176
2010-01-01	60.3660011291504
2011-01-01	59.1609992980957
2012-01-01	64.5080032348633
2013-01-01	59.2639999389648
2014-01-01	60.0589981079102
2015-01-01	59.8100013732910
2016-01-01	60.2299995422363
2017-01-01	60.3209991455078