Year	sq. km
1961	156000
1962	156000
1963	156000
1964	156000
1965	156000
1966	156000
1967	156000
1968	156000
1969	156000
1970	156000
1971	156000
1972	156000
1973	156000
1974	156000
1975	156000
1976	156000
1977	156000
1978	156000
1979	156000
1980	156000
1981	156000
1982	156000
1983	156000
1984	156000
1985	156000
1986	156000
1987	156000
1988	156000
1989	156000
1990	156000
1991	156000
1992	156000
1993	156000
1994	156000
1995	156000
1996	156000
1997	156000
1998	156000
1999	156000
2000	156000
2001	156000
2002	156000
2003	156000
2004	156000
2005	156000
2006	156000
2007	156000
2008	156000
2009	156000
2010	156000
2011	156000
2012	156000
2013	156000
2014	156000
2015	156000
2016	156000
2017	156000
2018	156000
2019	156000
2020	156000
2021	156000