Year % 1997 17.5182481751825 1998 17.5182481751825 1999 17.5182481751825 2000 10.6382978723404 2001 10.6382978723404 2002 10.6382978723404 2003 10.6382978723404 2004 21.9858156028369 2005 21.9858156028369 2006 24.822695035461 2007 22.6950354609929 2008 17.7304964539007 2009 19.1489361702128 2010 19.1489361702128 2011 19.1489361702128 2012 24.4604316546763 2013 24.113475177305 2014 24.113475177305 2015 23.4042553191489 2016 21.2765957446809 2017 21.2765957446809 2018 21.2765957446809 2019 21.2765957446809 2020 26.9503546099291 2021 27.6595744680851 2022 28.3687943262411 2023 28.3687943262411