Year % 2001 20.32642218190294 2002 30.08760992767172 2003 22.784908544245887 2004 28.3742727439966 2005 28.727138218733305 2006 39.243640492674544 2007 45.454289633824615 2008 36.02979934638226 2009 38.40389498150743 2010 40.37769912345298 2011 31.928131060816835 2012 36.51482557773836 2013 27.903895168536575 2014 27.918467208947632 2015 23.06329940194204 2016 17.723841875658607 2017 18.831126253109367 2018 20.618262549626493 2019 22.789630662093032