Year Percent 1999-12-31 3.338 2000-12-31 4.855 2001-12-31 3.294 2002-12-31 2.865 2003-12-31 2.124 2004-12-31 2.154 2005-12-31 2.488 2006-12-31 3.725 2007-12-31 4.684 2008-12-31 2.892 2009-12-31 0.7 2010-12-31 1.006 2011-12-31 1.356 2012-12-31 0.187 2013-12-31 0.287 2014-12-31 0.078 2015-12-31 -0.131 2016-12-31 -0.319 2017-12-31 -0.329 2018-12-31 -0.309 2019-12-31 -0.383