Year % 1999 10.19 2001 10.11 2002 10.26 2003 7.72 2004 7.08 2005 6.42 2006 6.42 2007 0.33 2008 0.32 2009 0.32 2010 0.31 2011 0.68 2012 0.68 2013 0.66 2015 0.66 2016 0.66 2020 0.59 2021 0.86