Year % 2000 40.3506578233819 2001 39.64154551304993 2002 39.06202832779394 2003 39.361759236367156 2004 38.243062168586306 2005 38.74358740737906 2006 38.78287109906584 2007 39.72048966022427 2008 40.14206101425542 2009 39.75424397802965 2010 39.48632910419172 2011 39.38001191067513 2012 39.21710770055114 2013 39.05225058451864 2014 39.02043167252531 2015 38.87328436959183 2016 38.6385016278155 2017 38.49068585855411 2018 38.48928842730513 2019 38.254219676452855