Year | Value | 2022 | 34.8 | 2021 | 38.8 | 2020 | 42.2 | 2019 | 34.8 | 2018 | 33.9 | 2017 | 33.7 | 2016 | 34.3 | 2015 | 34.6 | 2014 | 35.4 | 2013 | 37.6 | 2012 | 39.8 | 2011 | 41.6 | 2010 | 44.6 | 2009 | 47.3 | 2008 | 48.5 | 2005 | 53.5 | 2004 | 57.3 | 2003 | 58 | 2002 | 57.7 | 2001 | 67 | 2000 | 59.5 | 1999 | 64.3 | 1996 | 61.5 | 1992 | 54.2 | 1991 | 52.1 | 1989 | 55.4 | 1988 | 54.1 | 1980 | 60.6 |
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