Year Percent 1990-01-01 88.46440000000000 1991-01-01 91.23910000000000 1992-01-01 91.96840000000000 1993-01-01 91.84690000000000 1994-01-01 94.44050000000000 1995-01-01 98.83370000000000 1996-01-01 100.70100000000001 1997-01-01 101.40000000000000 1998-01-01 103.62600000000000 1999-01-01 97.33400000000000 2000-01-01 88.83450000000000 2001-01-01 87.94600000000000 2002-01-01 88.20990000000000 2003-01-01 88.41980000000000 2004-01-01 78.59940000000000 2005-01-01 67.18800000000000 2006-01-01 60.88540000000000 2007-01-01 60.17770000000000 2008-01-01 57.73060000000000 2009-01-01 59.29150000000000 2010-01-01 61.31090000000000 2011-01-01 59.09740000000000