Year Percent 1990-01-01 1.268330000000000 1991-01-01 1.560290000000000 1992-01-01 2.139720000000000 1993-01-01 2.609290000000000 1994-01-01 3.791450000000000 1995-01-01 5.009490000000000 1996-01-01 6.117300000000000 1997-01-01 7.092289999999999 1998-01-01 8.275089999999999 1999-01-01 8.717510000000000 2000-01-01 8.724980000000000 2001-01-01 9.479250000000000 2002-01-01 9.924480000000000 2003-01-01 10.433200000000000 2004-01-01 10.242600000000000 2005-01-01 9.828320000000000 2006-01-01 9.357320000000000 2007-01-01 8.695980000000000 2008-01-01 9.205219999999999 2009-01-01 21.448100000000000 2010-01-01 34.646800000000000 2011-01-01 36.014400000000000