Year % 1996 18.71 1999 15.2 2000 15.54 2001 11.61 2002 11.84 2003 11.5 2006 6.21 2007 11.08 2008 6.31 2009 11.58 2010 6.6 2011 6.84 2012 7.13 2013 8.01 2015 6.73 2016 6.58 2017 6.61 2018 3.74 2019 9.55 2020 6.51 2021 4.73