Year	sq. km
1961	439050
1962	439100
1963	439150
1964	439200
1965	439250
1966	439300
1967	439350
1968	439400
1969	439450
1970	439500
1971	439550
1972	439600
1973	439650
1974	439700
1975	439750
1976	439800
1977	439850
1978	439900
1979	439950
1980	440000
1981	440050
1982	440100
1983	440150
1984	440200
1985	440250
1986	440300
1987	440350
1988	440390
1989	440400
1990	440420
1991	440420
1992	440430
1993	440440
1994	440500
1995	440560
1996	440610
1997	440660
1998	440670
1999	440670
2000	440670
2001	440710
2002	440900
2003	441090
2004	441570
2005	441260
2006	440760
2007	440260
2008	441260
2009	441260
2010	441260
2011	440260
2012	440260
2013	441260
2014	441260
2015	441260
2016	441260
2017	441260
2018	441260
2019	441270
2020	441280
2021	441290