Year % 1997 17.568962380312566 1998 17.138565062607462 1999 9.81496970344474 2000 6.651056779943774 2001 6.923638421610152 2002 15.36571739670482 2003 20.310519839394768 2004 15.389052946558197 2005 11.307183626812076 2006 10.329285233890939 2007 11.244856121559433 2008 12.51245370072195 2009 13.998325815725687 2010 8.00540705848522 2011 16.366889793891747 2012 13.218585980085775 2013 12.396893103165722 2014 13.564750096958196 2015 7.291755357712802 2016 8.037660793520358 2017 18.40940395687284 2018 18.486625351416208 2019 13.64253842286959 2020 13.47592816549834 2021 13.02346041392978 2022 12.906261819909544 2023 15.854990546819817