Year Percent 1992 23.34163 1993 16.43845 1994 14.94755 1995 12.32939 1996 12.15216 1997 11.40678 1998 8.5658 1999 9.88635 2000 8.11078 2001 8.72483 2002 7.99591 2003 7.86221 2004 7.12296 2005 6.36952 2006 5.49583 2007 5.66029 2008 5.3158 2009 6.14688 2010 4.51053 2011 4.98897 2012 4.28833 2013 4.50355 2014 4.32955 2015 4.71055 2016 4.556 2017 4.51698 2018 4.39586 2019 4.46634 2020 5.39128 2021 5.03 2022 5.24714