Year % 2001 19.56443 2002 16.5199 2004 19.81414 2005 17.47167 2006 17.78652 2007 18.48429 2008 26.74866 2009 27.8301 2010 18.00311 2011 25.85196 2012 17.92966 2013 27.08992 2014 27.05138 2015 27.41683 2016 29.26784 2017 23.33642 2018 17.49724 2019 16.67317 2020 18.92477 2021 19.56634