| Year | Value | | 2022 | 35.786643254688 | | 2021 | 38.290847672172 | | 2020 | 28.065981547677 | | 2019 | 32.102995315595 | | 2018 | 25.09992382482 | | 2017 | 23.099669443404 | | 2016 | 24.017490166411 | | 2015 | 24.817554929302 | | 2014 | 29.857965105537 | | 2013 | 31.978571191958 | | 2012 | 37.23299840349 | | 2011 | 37.888549837404 | | 2010 | 36.987338597392 | | 2009 | 27.657873628119 | | 2008 | 38.658858637569 | | 2007 | 41.498970229751 | | 2006 | 43.454583587193 | | 2005 | 41.187653350209 | | 2004 | 33.536005509707 | | 2003 | 26.055461329442 | | 2002 | 28.876816246719 |
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