Month Percent 2010-06-30 3.7 2010-07-31 3.3 2010-08-31 5.5 2010-09-30 3.4 2010-10-31 13.9 2010-11-30 3.3 2010-12-31 5.6 2011-01-31 4 2011-02-28 5.6 2011-03-31 0.8 2011-04-30 15.1 2011-05-31 8.3 2011-06-30 10.9 2011-07-31 17.3 2011-08-31 10.6 2011-09-30 9.5 2011-10-31 5.8 2011-11-30 8.5 2011-12-31 -1 2012-01-31 5.3 2012-02-29 1.1 2012-03-31 2.7 2012-04-30 4.1 2012-05-31 14.4 2012-06-30 6.8 2012-07-31 1 2012-08-31 3.3 2012-09-30 -0.8 2012-10-31 -4.4 2012-11-30 1.7 2012-12-31 10.8 2013-01-31 7.3 2013-02-28 20.5