Year Percent 1999-01-01 1.7168500000000000 2000-01-01 1.6552400000000000 2001-01-01 1.7683000000000000 2002-01-01 1.0142400000000000 2003-01-01 1.1485500000000000 2004-01-01 0.7696160000000000 2005-01-01 0.9121500000000000 2006-01-01 1.0117300000000000 2007-01-01 0.8162060000000000 2008-01-01 0.9401649999999999 2009-01-01 0.9274950000000001 2010-01-01 0.9363379999999999 2011-01-01 0.9487810000000000 2012-01-01 0.9024230000000000 2013-01-01 0.8908410000000000 2014-01-01 0.8634139999999999 2015-01-01 0.8356220000000000