Year % 2002 35.39804 2003 35.99404 2005 48.05369 2006 30.92617 2007 25.80695 2008 33.75515 2009 33.4092 2010 32.21131 2011 31.98754 2012 30.7745 2013 28.95331 2014 29.01794 2015 32.27339 2016 32.846 2018 30.79019 2019 32.75741 2020 35.82627 2021 34.284