Year % 1990 14.2857142857143 1991 11.1111111111111 1992 10 1993 9.09090909090909 1994 15.3846153846154 1995 13.3333333333333 1996 11.1111111111111 1997 13.6363636363636 1998 12 1999 10 2000 11.4285714285714 2001 12.1951219512195 2002 10.6382978723404 2003 10.9090909090909 2004 9.52380952380952 2005 9.58904109589041 2006 9.52380952380952 2007 9.18367346938776 2008 9.64912280701754 2009 9.09090909090909 2010 9.21052631578947 2011 8.57142857142857 2012 8.45771144278607 2013 8.69565217391304 2014 8.3969465648855 2015 8.08080808080808 2016 8.08383233532934 2017 8.04289544235925 2018 7.97101449275362 2019 7.87746170678337 2020 7.76892430278884 2021 7.83242258652095 2022 7.70519262981575