Year % 2000 3.38045128072483 2001 3.34906855558355 2002 3.29094078340397 2003 2.94939903527601 2004 2.77249717173498 2005 2.58920403264852 2006 2.47356968851548 2007 2.20515261791615 2008 2.38806322207844 2009 2.10173510375679 2010 2.0448409310171 2011 1.77137519232662 2012 1.65369134689763 2013 1.62081058522944 2014 1.51368531881299 2015 1.50097276511241 2016 1.51653727288861 2017 1.46051242771208 2018 1.47806263952809 2019 1.50354925742649 2020 1.27661160623555