Year Percent 1997-01-01 0.12881099999999998 1998-01-01 0.14453000000000000 1999-01-01 0.15129200000000000 2000-01-01 0.18237100000000000 2001-01-01 0.22296000000000000 2002-01-01 0.31023800000000000 2003-01-01 0.44302299999999994 2004-01-01 0.50970900000000000 2005-01-01 0.51741600000000000 2006-01-01 0.67387299999999990 2007-01-01 0.97793500000000000 2008-01-01 0.95655100000000000 2009-01-01 1.20337000000000000 2010-01-01 1.67213000000000000 2011-01-01 2.06800999999999970