Year	sq. km
1961	3423500
1962	3451000
1963	3479500
1964	3508000
1965	3546000
1966	3582000
1967	3618000
1968	3654000
1969	3700000
1970	3746000
1971	3792500
1972	3838700
1973	3894800
1974	3961000
1975	4007100
1976	4066033.333
1977	4124966.667
1978	4184700
1979	4230375
1980	4276040
1981	4329090
1982	4425180
1983	4529280
1984	4645370
1985	4763470
1986	4824560
1987	4877660
1988	4933750
1989	4994850
1990	5056940
1991	5113790
1992	5143140
1993	5182230
1994	5228330
1995	5228330
1996	5228720
1997	5228722.5
1998	5228725
1999	5228727.5
2000	5228730
2001	5234668.444
2002	5240606.8889999995
2003	5246545.333000001
2004	5252483.778
2005	5258422.222
2006	5264360.666999999
2007	5270299.1110000005
2008	5276237.556
2009	5282176
2010	5274623
2011	5267130
2012	5259607
2013	5252084
2014	5244561
2015	5237038
2016	5229515
2017	5221992
2018	5214469
2019	5206950
2020	5206950
2021	5206950