Year % 2001 7.093831841749804 2002 5.880871443653135 2003 8.53637023388078 2004 9.255849138929225 2005 8.812522632548978 2006 10.724812785009455 2007 12.097647096938156 2008 18.30134943211033 2009 22.134613356438507 2010 22.99218645076148 2011 21.088853877638773 2012 20.500483477254356 2013 19.050348753503954 2014 19.18870157534335 2015 17.25046055456351 2016 18.940802401153405 2017 19.56550129406137 2018 17.989829705315604 2019 20.192352948837737 2020 21.69203199776586 2021 19.631611098916572 2022 17.362883666467607 2023 16.779974931863766