Year % 1996 12.15 1997 11.96 1998 11.96 1999 11.96 2000 11.96 2001 11.96 2002 10.76 2003 10.76 2007 8.8 2010 8.8 2011 9.01 2012 9.01 2015 8.8 2016 8.8 2021 8.49