Year % 2001 17.82214 2002 15.56677 2004 15.41776 2005 13.76323 2006 13.85681 2007 15.46573 2008 15.65534 2009 15.0598 2010 11.70165 2011 14.02491 2012 13.87411 2013 15.65855 2014 15.63109 2015 18.57999 2016 19.47977 2017 14.54692 2018 15.05086 2019 13.93071 2020 13.63516 2021 13.70189