Year % 1996 35.67 1997 24.03 1998 21.19 1999 36.4 2000 26.43 2001 21.27 2002 21.04 2003 19.57 2007 19.33 2010 21.31 2011 10.48 2012 20.46 2015 16.85 2016 7.22 2021 24.62