Year % 2001 13.651922878647282 2002 14.220259283564438 2003 13.789498013405407 2004 15.952051572726731 2005 18.038346663147724 2006 17.617572656611785 2007 19.067440695041807 2008 17.297531183456535 2009 20.3589468116486 2010 19.58752519920491 2011 16.8960727250315 2012 17.77218434382605 2013 16.812612680962168 2014 17.781753158608506 2015 18.474354286064397 2016 18.420278799793575 2017 23.137992399893513 2018 20.800611079218974 2019 20.59768237347715 2020 19.061984263612302 2021 16.13269471326266 2022 16.989600672894408 2023 16.15565924618188