Year	Percent
1980-01-01	35.16970000000000
1981-01-01	34.65920000000000
1982-01-01	34.16560000000000
1983-01-01	36.54530000000000
1984-01-01	37.46810000000000
1985-01-01	56.80840000000000
1986-01-01	78.60430000000000
1987-01-01	73.84450000000000
1988-01-01	65.19060000000000
1989-01-01	72.99210000000000
1990-01-01	69.84580000000000
1991-01-01	65.84200000000000
1992-01-01	71.58330000000000
1993-01-01	86.61460000000000
1994-01-01	98.83160000000000
1995-01-01	106.90700000000001
1996-01-01	118.55600000000000
1997-01-01	160.04000000000000
1998-01-01	214.52300000000000
1999-01-01	231.93700000000000
2000-01-01	256.47300000000000
2001-01-01	237.39700000000002
2002-01-01	196.72600000000000
2003-01-01	203.67400000000000
2004-01-01	204.91600000000000
2005-01-01	215.95900000000000
2006-01-01	249.23800000000000
2007-01-01	263.74700000000000
2008-01-01	208.38800000000000
2009-01-01	178.66400000000002
2010-01-01	200.38400000000001
2011-01-01	181.54400000000000
2012-01-01	169.91900000000000
2013-01-01	202.83400000000000
2014-01-01	215.93200000000002
2015-01-01	216.56799999999998
2016-01-01	216.26300000000000
2017-01-01	228.24400000000003