| Year | Value | | 2021 | 36.154994891142 | | 2020 | 36.154994891142 | | 2019 | 36.154994891142 | | 2018 | 36.154994891142 | | 2017 | 36.154994891142 | | 2016 | 36.154994891142 | | 2015 | 36.154994891142 | | 2014 | 36.023998532841 | | 2013 | 35.893158903643 | | 2012 | 35.768096953816 | | 2011 | 35.637078283655 | | 2010 | 35.506059613495 | | 2009 | 35.537722458784 | | 2008 | 35.616048977807 | | 2007 | 35.647753361758 | | 2006 | 35.679457745709 | | 2005 | 35.71116212966 | | 2004 | 35.731147540984 | | 2003 | 35.762841530055 | | 2002 | 35.794535519126 | | 2001 | 35.826229508197 | | 2000 | 35.857923497268 | | 1999 | 35.986885245902 | | 1998 | 36.115846994536 | | 1997 | 36.244808743169 | | 1996 | 36.373770491803 | | 1995 | 36.502732240437 | | 1994 | 36.631693989071 | | 1993 | 36.760655737705 | | 1992 | 36.889617486339 | | 1991 | 37.018579234973 | | 1990 | 37.147540983607 |
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