Year % 1992 0 1995 24.50037 1996 24.72918 1997 28.61591 1998 35.83875 1999 34.55595 2000 25.81769 2001 24.39988 2002 30.46956 2004 18.58995 2005 11.86416 2006 12.21152 2007 11.61638 2008 10.71429 2009 11.04621 2010 11.21799 2011 11.97183 2012 13.45941 2013 15.33845 2014 15.28302 2015 15.14908 2016 16.47659 2017 16.82448 2018 16.64311 2019 16.66486 2020 15.84492 2021 15.77976