Year % 2001 15.03 2002 9.61 2004 9.69 2005 8.5 2006 8.04 2007 6.37 2008 6.23 2009 9.56 2010 7.89 2011 7.85 2012 7.82 2013 9.43 2014 7.22 2015 7.03 2016 7.03 2017 5.24 2018 5.2 2019 4.64 2020 3.71 2021 6.44