Year Percent 1991-01-01 1.6855200000000001 1992-01-01 7.9577600000000000 1993-01-01 13.9702000000000000 1994-01-01 6.8510600000000000 1995-01-01 5.5220300000000000 1996-01-01 6.2435400000000000 1997-01-01 5.8200699999999990 1998-01-01 9.7604800000000010 1999-01-01 12.9620000000000000 2000-01-01 10.9027000000000000 2001-01-01 9.5237800000000000 2002-01-01 8.9726900000000000 2003-01-01 7.9762800000000000 2004-01-01 7.6289500000000000 2005-01-01 7.1715500000000000 2006-01-01 5.8245200000000000 2007-01-01 4.5951900000000006 2008-01-01 3.8111000000000000 2009-01-01 3.6944199999999996 2010-01-01 3.1578300000000000 2011-01-01 2.7638400000000000 2012-01-01 2.4618900000000004 2013-01-01 2.0795900000000000 2014-01-01 1.8710000000000000 2015-01-01 1.7413500000000000 2016-01-01 6.4406000000000000