Year % 1991 6.57 1992 12.35 1994 12.35 1995 13.95 1996 12.02 1997 12.02 1998 12.06 1999 12.1 2000 12.11 2001 12.11 2002 12.14 2003 12.13 2004 12.14 2005 12.12 2006 12.13 2007 12.12 2008 12.08 2009 12.06 2010 12.06 2011 7.34 2012 5.27 2013 5.37 2014 4.87 2015 3.85 2016 3.9 2017 7.69 2018 4.99 2019 4.57 2020 4.55 2021 5.47