Year | Value | 2021 | 180 | 2020 | 180 | 2019 | 180 | 2018 | 180 | 2017 | 180 | 2016 | 180 | 2015 | 180 | 2014 | 180 | 2013 | 180 | 2012 | 180 | 2011 | 180 | 2010 | 180 | 2009 | 180 | 2008 | 180 | 2007 | 180 | 2006 | 180 | 2005 | 180 | 2004 | 180 | 2003 | 180 | 2002 | 180 | 2001 | 180 | 2000 | 180 | 1999 | 180 | 1998 | 180 | 1997 | 180 | 1996 | 180 | 1995 | 180 | 1994 | 180 | 1993 | 180 | 1992 | 180 | 1991 | 180 | 1990 | 180 | 1989 | 180 | 1988 | 180 | 1987 | 180 | 1986 | 180 | 1985 | 180 | 1984 | 180 | 1983 | 180 | 1982 | 180 | 1981 | 180 | 1980 | 180 | 1979 | 180 | 1978 | 180 | 1977 | 180 | 1976 | 180 | 1975 | 180 | 1974 | 180 |
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