Year % 1997 4.80769230769231 1999 8.91089108910891 2000 7.92079207920792 2001 12.8712871287129 2002 12.8712871287129 2003 12.8712871287129 2004 15.8415841584158 2005 21.7821782178218 2006 21.7821782178218 2007 21.7821782178218 2008 21.7821782178218 2009 23.7623762376238 2010 18.8118811881188 2011 19.8019801980198 2012 19.8019801980198 2013 19.8019801980198 2014 17.8217821782178 2015 21.7821782178218 2016 21.7821782178218 2017 22.7722772277228 2018 22.7722772277228 2019 25.7425742574257 2020 24.7524752475248 2021 39.6039603960396 2022 40.5940594059406 2023 38.6138613861386