Year % 1989 24.78 1990 23.15 1993 16.74 1995 14.01 1996 10.76 1997 20.57 1998 7.93 1999 9.86 2000 8.02 2001 6.13 2002 6.28 2003 5.74 2004 5.81 2005 5.78 2006 5.82 2007 5.57 2008 6.84 2009 4.96 2010 5.18 2011 5.3 2012 5.43 2013 5.37 2016 6.31 2017 5.86 2018 6.25 2019 6.71 2020 6.29 2021 6.02