Year Percent 1999-01-01 3.02718543595638 2000-01-01 2.48397483343994 2001-01-01 2.48431535145997 2002-01-01 2.45227845318762 2003-01-01 2.88783427479606 2004-01-01 2.96722294049915 2005-01-01 2.58873710032216 2006-01-01 2.10092555643631 2007-01-01 2.03667992766870 2008-01-01 1.84907575813271 2009-01-01 3.20878747403450 2010-01-01 3.93812624867185 2011-01-01 3.97861246147455 2012-01-01 3.91727195980865 2013-01-01 3.60503167016955 2014-01-01 3.39618441699442