Year Percent 1979-01-01 54.12060000000000 1980-01-01 43.58010000000000 1981-01-01 92.82340000000000 1982-01-01 62.83350000000000 1983-01-01 51.24910000000000 1984-01-01 71.78230000000000 1985-01-01 61.68400000000000 1986-01-01 104.21700000000001 1987-01-01 108.60200000000000 1988-01-01 129.94400000000000 1989-01-01 98.08160000000000 1990-01-01 59.86390000000000 1991-01-01 79.63040000000000 1992-01-01 114.91600000000000 1993-01-01 171.37400000000002 1994-01-01 171.30200000000002 1995-01-01 95.58240000000000 1996-01-01 111.84000000000000 1997-01-01 211.54500000000000 1998-01-01 222.83599999999998 1999-01-01 347.56500000000000 2000-01-01 199.72500000000000 2001-01-01 193.06099999999998 2002-01-01 234.82400000000000 2003-01-01 153.76600000000000 2004-01-01 135.41899999999998 2005-01-01 199.36300000000000 2006-01-01 165.85600000000000 2007-01-01 193.42200000000000 2008-01-01 164.45300000000000 2009-01-01 271.66700000000003 2010-01-01 161.26700000000000 2011-01-01 179.29800000000000 2012-01-01 146.39200000000000 2013-01-01 108.28900000000000 2014-01-01 102.19800000000000 2015-01-01 155.74200000000002 2016-01-01 130.34200000000000 2017-01-01 130.84799999999998