Year % 1991 33.93 1993 4.6 1996 4.3 1997 4.24 1998 4.09 1999 3.9 2000 3.66 2001 1.06 2002 1.08 2003 1.08 2004 1.08 2005 1.08 2006 1.03 2007 1.13 2008 3.84 2009 1.12 2010 1.11 2011 1.12 2012 0.99 2013 0.99 2014 0.98 2015 0.98 2016 0.98 2017 0.99 2018 0.98 2019 0.98 2020 0.98 2021 0.98