Year Percent 2003-01-01 3.122610000000000 2004-01-01 5.027480000000001 2005-01-01 6.192290000000000 2006-01-01 3.570000000000000 2007-01-01 3.720000000000000 2008-01-01 2.470000000000000 2009-01-01 2.590000000000000 2010-01-01 3.030000000000000 2011-01-01 4.050000000000000 2012-01-01 5.000000000000000 2013-01-01 6.100000000000000 2014-01-01 7.060000000000000 2015-01-01 7.270000000000000 2016-01-01 7.340000000000000