Year | Value | 2018 | 46.565647157081 | 2017 | 47.625769158978 | 2016 | 47.680244814161 | 2015 | 50.848592395052 | 2014 | 50.613101942525 | 2013 | 51.004715336871 | 2012 | 51.278884163218 | 2011 | 52.180609263211 | 2010 | 52.033066985491 | 2009 | 56.356525867853 | 2008 | 57.099081278781 | 2007 | 58.281438269178 | 2006 | 60.560895734873 | 2005 | 63.096877850714 | 2004 | 63.933566962019 | 2003 | 60.998300251223 | 2002 | 61.48376793384 | 2001 | 58.240308301216 | 2000 | 56.412959170308 | 1999 | 53.023808218394 | 1998 | 54.640671890079 | 1997 | 51.713362322153 | 1996 | 47.590025957728 | 1995 | 49.363552096294 | 1994 | 51.374496946925 | 1993 | 56.083672105885 | 1992 | 53.793906730196 | 1991 | 54.359724039666 | 1990 | 55.10882587988 |
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