Year	sq. km
1961	318000
1962	318000
1963	318000
1964	318000
1965	318000
1966	318000
1967	318000
1968	318000
1969	318000
1970	318000
1971	318000
1972	318000
1973	318000
1974	318000
1975	318000
1976	318000
1977	318000
1978	318000
1979	318000
1980	318000
1981	318000
1982	318000
1983	318000
1984	318000
1985	318000
1986	318000
1987	318000
1988	318000
1989	318000
1990	318000
1991	318000
1992	318000
1993	318000
1994	318000
1995	318000
1996	318000
1997	318000
1998	318000
1999	318000
2000	318000
2001	318000
2002	318000
2003	318000
2004	318000
2005	318000
2006	318000
2007	318000
2008	318000
2009	318000
2010	318000
2011	318000
2012	318000
2013	318000
2014	318000
2015	318000
2016	318000
2017	318000
2018	318000
2019	318000
2020	318000
2021	318000