Year % 2004 28.607 2005 26.258 2006 29.413 2008 29.93 2009 34.43 2010 32.139 2011 30.155 2012 32.343 2013 36.493 2014 38.637 2017 32.629 2018 33.178 2019 33.136 2020 36.984 2021 37.36 2022 37.91 2023 37.982