Year	Percent
1977-01-01	26.89090000000000
1978-01-01	24.05110000000000
1979-01-01	27.18740000000000
1980-01-01	32.77280000000000
1981-01-01	36.80260000000000
1982-01-01	39.10050000000000
1983-01-01	40.95040000000000
1984-01-01	42.95800000000000
1985-01-01	53.10080000000000
1986-01-01	52.92220000000000
1987-01-01	58.24370000000000
1988-01-01	57.70470000000000
1989-01-01	61.81890000000000
1990-01-01	68.30060000000000
1991-01-01	74.52880000000000
1992-01-01	77.41990000000000
1993-01-01	82.72450000000000
1994-01-01	85.82350000000000
1995-01-01	88.53390000000000
1996-01-01	96.01270000000000
1997-01-01	105.62299999999999
1998-01-01	115.73400000000000
1999-01-01	124.52300000000000
2000-01-01	127.57000000000000
2001-01-01	131.43200000000002
2002-01-01	135.83300000000000
2003-01-01	139.23400000000000
2004-01-01	139.81500000000000
2005-01-01	139.15900000000000
2006-01-01	141.52800000000000
2007-01-01	137.39200000000000
2008-01-01	139.75000000000000
2009-01-01	154.34600000000000
2010-01-01	161.82200000000000
2011-01-01	163.43700000000000
2012-01-01	168.97200000000000
2013-01-01	174.69299999999998
2014-01-01	180.83100000000000
2015-01-01	187.72099999999998
2016-01-01	197.81599999999997