Year Percent 1997-01-01 0.30801600000000000 1998-01-01 4.74972000000000000 1999-01-01 6.13577000000000000 2000-01-01 6.13577000000000000 2001-01-01 6.13577000000000000 2002-01-01 4.23185000000000000 2003-01-01 2.68324000000000000 2004-01-01 2.39083000000000000 2005-01-01 2.68427000000000000 2006-01-01 2.70547000000000000 2007-01-01 2.99602999999999970 2008-01-01 3.09734000000000000 2009-01-01 2.56740000000000000 2010-01-01 2.81669000000000040 2011-01-01 4.14152000000000000 2012-01-01 1.16373000000000000 2013-01-01 0.35496300000000003 2014-01-01 1.88687000000000000 2015-01-01 2.67789000000000000 2016-01-01 1.91457000000000000