Year	Percent
1983-01-01	428.00500000000000
1984-01-01	325.78500000000000
1985-01-01	373.68800000000005
1986-01-01	405.87900000000000
1987-01-01	449.21900000000000
1988-01-01	420.18500000000000
1989-01-01	434.64500000000000
1990-01-01	399.39400000000000
1991-01-01	360.68800000000005
1992-01-01	318.39799999999997
1993-01-01	312.30900000000000
1994-01-01	338.51300000000003
1995-01-01	354.81500000000000
1996-01-01	308.02400000000000
1997-01-01	302.09000000000000
1998-01-01	289.47400000000000
1999-01-01	288.38800000000000
2000-01-01	283.83299999999997
2001-01-01	269.17100000000000
2002-01-01	235.35700000000000
2003-01-01	237.34500000000000
2004-01-01	241.44500000000000
2005-01-01	238.65900000000002
2006-01-01	275.80000000000000
2007-01-01	295.91600000000000
2008-01-01	290.18600000000000
2009-01-01	289.23600000000000
2010-01-01	304.52500000000000
2011-01-01	305.61400000000003
2012-01-01	261.15900000000000
2013-01-01	205.80700000000002
2014-01-01	172.26600000000000
2015-01-01	158.51800000000000
2016-01-01	141.11400000000000