Year % 1997 3.52941176470588 1998 3.52941176470588 1999 7.3394495412844 2000 7.3394495412844 2001 7.3394495412844 2002 7.3394495412844 2005 10.4761904761905 2006 10.4761904761905 2007 10.4761904761905 2008 10.4761904761905 2009 9.61538461538462 2010 9.61538461538462 2011 12.5 2012 12.5 2016 7.19424460431655 2017 8.57142857142857 2018 8.57142857142857 2019 8.57142857142857 2020 8.57142857142857 2021 12.8571428571429 2022 12.8571428571429 2023 12.8571428571429