Year % 1988 77.05187 1989 77.07732 1990 58.1488 1992 58.04268 1993 55.82905 1994 55.27732 1995 54.9138 1996 43.71161 1997 33.50117 1998 23.06363 1999 21.10225 2000 7.062637 2001 6.300935 2002 0.5252777 2003 0.4634719 2004 4.344157 2005 4.344157 2006 4.317612 2007 16.14054 2008 4.303794 2009 4.900824 2010 4.898273 2011 3.32518 2012 2.995271 2013 3.626711 2015 3.655122 2016 4.158388 2017 11.11249 2018 3.216621 2019 3.008031 2020 3.736443 2021 2.657317