Year % 1997 15.6862745098039 1998 15.6862745098039 1999 15.6862745098039 2001 17.6470588235294 2002 17.6470588235294 2003 17.6470588235294 2004 19.6078431372549 2005 25.4901960784314 2006 25.4901960784314 2007 25.4901960784314 2008 25.4901960784314 2009 25.4901960784314 2010 9.80392156862745 2011 11.7647058823529 2012 11.7647058823529 2013 11.7647058823529 2014 11.7647058823529 2015 25.4901960784314 2016 25.4901960784314 2017 25.4901960784314 2018 25.4901960784314 2019 31.3725490196078 2020 29.4117647058824 2021 29.4117647058824 2022 29.4117647058824 2023 29.4117647058824