Year sq. km 1961 407339.7 1962 407339.7 1963 407339.7 1964 407339.7 1965 407339.7 1966 407339.7 1967 407339.7 1968 407339.7 1969 407339.7 1970 407339.7 1971 407339.7 1972 407339.7 1973 407339.7 1974 407339.7 1975 407339.7 1976 407339.7 1977 407339.7 1978 407339.7 1979 407339.7 1980 407339.7 1981 407339.7 1982 407339.7 1983 407339.7 1984 407339.7 1985 407339.7 1986 407339.7 1987 407339.7 1988 407339.7 1989 407339.7 1990 407339.7 1991 407339.7 1992 407339.7 1993 407339.7 1994 407339.7 1995 407339.7 1996 407339.7 1997 407339.7 1998 407339.7 1999 407339.7 2000 407339.7 2001 407339.7 2002 407339.7 2003 407339.7 2004 407339.7 2005 407339.7 2006 407339.7 2007 407339.7 2008 407339.7 2009 407339.7 2010 407339.7 2011 407339.7 2012 407339.7 2013 407339.7 2014 407339.7 2015 407310.64 2016 407310.64 2017 407310.64 2018 407310.64 2019 407283.59 2020 407283.532 2021 407283.54