Year % 1997 22.7504244482173 1998 27.6206322795341 1999 27.6206322795341 2000 27.6206322795341 2001 27.6206322795341 2002 27.6206322795341 2003 35.9605911330049 2004 35.9605911330049 2005 35.9605911330049 2006 35.9605911330049 2007 35.9605911330049 2008 43.1596091205212 2009 43.1596091205212 2010 43.1596091205212 2011 45.221843003413 2012 45.221843003413 2013 48.8562091503268 2014 48.8562091503268 2015 48.8562091503268 2016 48.8562091503268 2017 48.8562091503268 2018 53.2231404958678 2019 53.2231404958678 2020 53.2231404958678 2021 53.4129692832764 2022 53.4129692832764 2023 55.7446808510638