Year % 2000 2.14086468417512 2001 2.03809671962127 2002 1.90159147329136 2003 1.84901813260068 2004 1.52596396248757 2005 1.43308508194398 2006 1.15009006492505 2007 1.16348754693909 2008 1.15511788346895 2009 0.958765205140195 2010 0.895590561132242 2011 0.878855746487958 2012 0.844698144421414 2013 0.726318879690997 2014 0.699239636338879 2015 0.725330282298414 2016 0.746173693101889 2017 0.736818054562052 2018 0.766580779311703 2019 0.647047925786663 2020 0.624238936691713