Year % 1997 6.74846625766871 1998 7.36196319018405 1999 11.5384615384615 2000 11.5384615384615 2001 11.5384615384615 2002 11.5384615384615 2003 11.5384615384615 2004 22.7513227513228 2005 22.7513227513228 2006 22.7513227513228 2007 22.7513227513228 2008 22.7513227513228 2009 27.5700934579439 2010 27.5700934579439 2011 26.7281105990783 2012 26.7281105990783 2013 26.7281105990783 2014 31.3364055299539 2015 31.3364055299539 2016 31.3364055299539 2017 31.3364055299539 2018 31.3364055299539 2019 22.5806451612903 2020 24.8847926267281 2021 26.2672811059908 2022 26.2672811059908 2023 16.2337662337662