Year % 1992 8.968296 1996 13.07131 1997 13.07221 1998 13.07221 1999 12.37892 2000 12.35282 2001 10.28755 2002 10.25295 2003 9.978548 2004 19.26837 2005 19.74796 2006 20.18741 2007 19.57359 2008 14.90985 2009 14.46776 2010 21.67292 2011 12.90381 2014 6.459964 2016 6.283561 2017 0 2018 0 2019 0 2020 0 2021 0