Year % 1988 13.11 1991 11.78 1993 9.8 1996 6.51 1997 7.19 1998 6.99 1999 7.29 2000 6.28 2001 7.33 2002 2.12 2003 5.56 2004 7.55 2005 2.24 2006 3.82 2007 5.08 2008 4.99 2009 5.04 2010 3.63 2011 3.85 2012 4.04 2013 4.62 2014 0.79 2016 3.52 2020 3.04 2021 3.15