Year % 2003 11.1368319737237 2004 10.6508759339031 2005 10.6061629754371 2006 10.5122870241772 2007 11.7860758383678 2008 12.613661031724 2009 12.5949095429662 2010 12.4309074825758 2011 12.0392476435812 2012 11.9382231731097 2013 12.3092064569271 2014 12.2451141965134 2015 13.0404516611354 2016 11.8708740707555 2017 11.6634300716691 2018 11.7769971865356 2019 11.9147627822343 2020 11.9593666528017 2021 11.6143164933212 2022 11.2402028697542