Year Percent 1998-01-01 7.00005585664910 1999-01-01 6.19868227441754 2000-01-01 5.23064373614234 2001-01-01 4.65972425436216 2002-01-01 4.89245204609630 2003-01-01 4.90045464068780 2004-01-01 4.63617301321257 2005-01-01 4.34159215709168 2006-01-01 3.94818738021894 2007-01-01 3.51037717204698 2008-01-01 3.29223705875198 2009-01-01 4.71102838701019 2010-01-01 4.82156920111697 2011-01-01 4.46826560032522 2012-01-01 4.37078862171651 2013-01-01 4.60140201375370