Year	sq. km
1961	5144770
1962	5144770
1963	5144770
1964	5144770
1965	5144770
1966	5144770
1967	5144770
1968	5144770
1969	5144770
1970	5144770
1971	5144770
1972	5144770
1973	5144770
1974	5144770
1975	5144770
1976	5144770
1977	5144770
1978	5144770
1979	5144770
1980	5144770
1981	5144770
1982	5144770
1983	5144770
1984	5144770
1985	5144770
1986	5144770
1987	5144770
1988	5144770
1989	5144770
1990	5144770
1991	5144770
1992	5144770
1993	5144770
1994	5137847
1995	5137847
1996	5137847
1997	5137847
1998	5137847
1999	5137847
2000	5137847
2001	5137847
2002	5137847
2003	5137847
2004	5136164
2005	5136164
2006	5136164
2007	5136164
2008	5136164
2009	5136164
2010	5136164
2011	5136164
2012	5136164
2013	5136164
2014	5135334
2015	5135334
2016	5135334
2017	5135681
2018	5135270
2019	5135270
2020	5135270
2021	5135270