Year Percent 2001-01-01 2.16699398769567 2002-01-01 2.22862880994596 2003-01-01 2.49561717378781 2004-01-01 2.95542255598416 2005-01-01 3.59933142017811 2006-01-01 3.58489011896920 2007-01-01 3.22705405472316 2008-01-01 3.29077984716000 2009-01-01 3.99294512640623 2010-01-01 4.22255247536721 2011-01-01 3.89743187437539 2012-01-01 3.89977736395172 2013-01-01 4.02012529626407 2014-01-01 3.95215824051382