Year % 2001 16.54085162723157 2002 16.878583754204428 2003 17.993159023340894 2004 20.24120959562029 2005 18.756101417040938 2006 19.149638649623206 2007 18.74942307635045 2008 20.881441990242678 2009 23.671038840106682 2010 25.22866108005413 2011 23.999490271778097 2012 22.65474707671615 2013 21.82264111559798 2014 22.178426219562787 2015 22.858005817700025 2016 22.568272649999336 2017 23.08813402848612 2018 22.26455324083708 2019 22.166737645664313 2020 27.295637914703786 2021 27.008772574457495 2022 24.64092265038066 2023 22.555946922819793