Year % 1999 11.87 2001 11.79 2002 12.46 2003 10.22 2004 9.66 2005 9.05 2006 9.12 2007 4.05 2008 4.03 2009 4.03 2010 4.03 2011 4.03 2012 4.05 2013 3.84 2015 3.84 2016 3.84 2020 3.63 2021 3.95