Year % 1997 1.23456790123457 1998 1.23456790123457 2000 4.93827160493827 2001 4.93827160493827 2002 4.93827160493827 2003 7.40740740740741 2004 6.17283950617284 2005 7.40740740740741 2006 8.64197530864197 2007 11.1111111111111 2008 11.1111111111111 2009 11.1111111111111 2010 11.1111111111111 2011 11.1111111111111 2012 11.1111111111111 2013 15.3846153846154 2014 17.5824175824176 2015 17.5824175824176 2016 17.5824175824176 2017 17.5824175824176 2018 17.5824175824176 2019 16.4835164835165 2020 18.6813186813187 2021 18.6813186813187 2022 18.6813186813187 2023 19.7802197802198