Year	sq. km
1961	395220
1962	395220
1963	395230
1964	395230
1965	395230
1966	395230
1967	395230
1968	395230
1969	395330
1970	395330
1971	394930
1972	394930
1973	394800
1974	394500
1975	394460
1976	394490
1977	394500
1978	394460
1979	394490
1980	394640
1981	394840
1982	395040
1983	395240
1984	395350
1985	395550
1986	395750
1987	395950
1988	396150
1989	396350
1990	396560
1991	396660
1992	396780
1993	396900
1994	397100
1995	397100
1996	397100
1997	397100
1998	397100
1999	397100
2000	397100
2001	397100
2002	397100
2003	397100
2004	397100
2005	397100
2006	397100
2007	397100
2008	397100
2009	397100
2010	397100
2011	397100
2012	397100
2013	397100
2014	397100
2015	397100
2016	397100
2017	397100
2018	397100
2019	397100
2020	397100
2021	397100