Year	sq. km
1961	646680
1962	646360
1963	645740
1964	646120
1965	644720
1966	645000
1967	644230
1968	645220
1969	644240
1970	643470
1971	642960
1972	641710
1973	640360
1974	639950
1975	638840
1976	640980
1977	640430
1978	639740
1979	638610
1980	637680
1981	636270
1982	636070
1983	635970
1984	636460
1985	636310
1986	635950
1987	636280
1988	635770
1989	632060
1990	631840
1991	631610
1992	628120
1993	624860
1994	621440
1995	615910
1996	610780
1997	610260
1998	605100
1999	604520
2000	591050
2001	575370
2002	556442.6
2003	547221.2
2004	539010.9
2005	539333.9
2006	537651.5
2007	526982
2008	529461.7
2009	529073.9
2010	519523.8
2011	521343.5
2012	517581.80000000005
2013	518923.1
2014	518221.4
2015	519245.9
2016	516233.8
2017	515348.60000000003
2018	516300
2019	521123.38999999996
2020	511648.336
2021	510363.028