Year	sq. km
1961	4217020
1962	4217190
1963	4220510
1964	4222000
1965	4225330
1966	4226410
1967	4233600
1968	4237730
1969	4245470
1970	4254190
1971	4272170
1972	4287600
1973	4287160
1974	4294510
1975	4291630
1976	4301170
1977	4304200
1978	4310200
1979	4311890
1980	4322830
1981	4281376
1982	4284913.4
1983	4291507.4
1984	4347793.6
1985	4415838
1986	4495378
1987	4571120
1988	4653330
1989	4722858
1990	4778892
1991	4785769
1992	4807704.8
1993	4913206.8
1994	5002289.896
1995	5088065.327
1996	5169300.405
1997	5238830.532
1998	5321573.175
1999	5393146.998
2000	5397877.131
2001	5400981.989
2002	5410951.731000001
2003	5436546.769
2004	5443305.778
2005	5451098.859
2006	5460826.103
2007	5467966.8889999995
2008	5459721.164
2009	5460153
2010	5465344.5
2011	5467539.764
2012	5212816.327
2013	5219117.740999999
2014	5218516.3549999995
2015	5223517.789
2016	5232064.896
2017	5238175.132999999
2018	5236246.657
2019	5228038.142999999
2020	5236720.505999999
2021	5236390.685