Year % 1989 17.06409 1993 15.0743 1995 14.79871 1996 13.39591 1997 12.16562 1998 11.39582 1999 10.86859 2000 10.59767 2001 11.22468 2002 11.5399 2003 7.986491 2004 8.124207 2005 8.074893 2006 8.019535 2007 8.239651 2008 8.418102 2009 8.697151 2010 8.158904 2011 7.961274 2012 9.278472 2013 8.667514 2014 8.631402 2015 8.654757 2016 8.349237 2017 5.197579 2018 5.181158 2019 4.969921 2020 5.164937 2021 5.774917