Year	sq. km
1961	4744844.445
1962	4765929.315
1963	4793695.782
1964	4819038.096
1965	4862591.91
1966	4870285.257
1967	4895805.6389999995
1968	5135695.6110000005
1969	5108880.188999999
1970	4934324.985
1971	4995361.666999999
1972	4998150
1973	4978970
1974	5003570
1975	4995470
1976	5007420
1977	4915100
1978	4961000
1979	4932380
1980	4956380
1981	4955650
1982	4907720
1983	4837890
1984	4865580
1985	4867910
1986	4685410
1987	4710200
1988	4720520
1989	4671040
1990	4644370
1991	4627820
1992	4660040
1993	4600970
1994	4691430
1995	4633880
1996	4652300
1997	4622330
1998	4638810
1999	4536930
2000	4554690
2001	4557000
2002	4470000
2003	4395000
2004	3949060
2005	4102300
2006	4093020
2007	3983555
2008	3892880
2009	3842570
2010	3763720
2011	3961210
2012	3870760
2013	3717750
2014	3744230
2015	3481190
2016	3426020
2017	3718370
2018	3588950
2019	3624770
2020	3557750
2021	3635190