Year % 2001 10.84 2002 13.17 2005 10.95 2007 9.7 2008 9.83 2009 7.38 2010 6.77 2011 6.15 2013 5.45 2015 3.38 2016 3.38 2017 3.57 2018 3.71 2021 4.14