Year sq. km 1961 447400 1962 447400 1963 447400 1964 447400 1965 447400 1966 447400 1967 447400 1968 447400 1969 447400 1970 447400 1971 447400 1972 447400 1973 447400 1974 447400 1975 447400 1976 447400 1977 447400 1978 447400 1979 447400 1980 447400 1981 447400 1982 447400 1983 447400 1984 447400 1985 447400 1986 447400 1987 447400 1988 447400 1989 447400 1990 447400 1991 447400 1992 447400 1993 447400 1994 447400 1995 447400 1996 447400 1997 447400 1998 447400 1999 447400 2000 444103 2001 444103 2002 444103 2003 444103 2004 444103 2005 444103 2006 444103 2007 444103 2008 444103 2009 444103 2010 444103 2011 444103 2012 444103 2013 444103 2014 444103 2015 448924 2016 448924 2017 448924 2018 448924 2019 448924 2020 448924 2021 448924