| Year | Value | | 2024 | 26.619234493008 | | 2023 | 33.254836025456 | | 2022 | 35.330084374067 | | 2021 | 41.637512469357 | | 2020 | 41.039652389344 | | 2019 | 33.460074457072 | | 2018 | 29.399992720809 | | 2017 | 29.57341796736 | | 2016 | 30.075201418508 | | 2015 | 29.145145266046 | | 2014 | 31.120673501675 | | 2013 | 31.78364652808 | | 2012 | 37.699717468463 | | 2011 | 39.969342532381 | | 2010 | 45.179741184004 | | 2009 | 48.48714012081 | | 2008 | 41.031881301561 | | 1998 | 30.286378742005 | | 1997 | 31.879375228231 | | 1996 | 27.48472228429 | | 1995 | 25.857096435694 | | 1994 | 44.017505710522 | | 1993 | 33.698223256241 | | 1992 | 34.01727506201 | | 1991 | 32.129911132363 | | 1990 | 30.245494201652 |
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