Year Percent 2001-01-01 2.79134855650406 2002-01-01 2.95223207282856 2003-01-01 3.30104964315092 2004-01-01 3.70154364212572 2005-01-01 4.16709166601405 2006-01-01 3.83346146218778 2007-01-01 3.29269968124719 2008-01-01 3.34739196019520 2009-01-01 4.83038796759213 2010-01-01 4.88504107422078 2011-01-01 4.41907017273418 2012-01-01 4.63607275797846 2013-01-01 4.65545495491879 2014-01-01 4.68601837660648