Year % 2000 16.322259281127884 2001 15.868675835027192 2002 15.595078807334806 2003 15.332808854789157 2004 14.842240612600314 2005 14.562897386823288 2006 14.190629354265184 2007 13.954794208280402 2008 13.713019980139057 2009 13.503380143693288 2010 13.227272503283563 2011 12.962152654832462 2012 12.800736476437963 2013 12.58094179608776 2014 12.416614668862055 2015 12.41318110071112 2016 12.342094624290569 2017 12.133093057633559 2018 11.944953532232125 2019 11.832563290916081