Year % 2000 3.76852515615772 2001 3.37632291622897 2002 3.32300661185077 2003 3.2116412050563 2004 2.80015266064712 2005 2.67018462123514 2006 2.56427986943677 2007 2.56279968312447 2008 2.6107541776914 2009 2.22323633588977 2010 2.22153576750398 2011 2.11208881176804 2012 1.82308572232925 2013 1.81751497022414 2014 1.72552026502172 2015 1.73125202065024 2016 1.69018184333307 2017 1.44046141963872 2018 1.36024638198396 2019 1.33584120538789 2020 1.29738455640649