Year % 1993 8.7 1995 12.19 1996 26.02 1997 23.77 1998 25.97 1999 27.86 2000 29.08 2001 28.81 2002 29.14 2003 28.54 2004 28.09 2005 27.71 2006 27.8 2007 29.66 2008 27.72 2009 28.58 2010 28.45 2011 27.42 2013 29.37 2015 31.92 2016 29.54 2017 29.64 2018 28.76 2019 31.1 2020 28.79 2021 29.18