Year	sq. km
1961	5150150
1962	5186440
1963	5218689
1964	5256968
1965	5289597
1966	5319935
1967	5346764
1968	5382593
1969	5406182
1970	5448901
1971	5504890
1972	5560198
1973	5605539.227
1974	5649989.455
1975	5698741.682
1976	5756632.909
1977	5823004.136
1978	5883265.364
1979	5941167.591
1980	6000993.898
1981	6032724.045
1982	6059405.273
1983	6110016.5
1984	6145738.727
1985	6170162.025
1986	6168967.182
1987	6171785.009
1988	6169004.636
1989	6169394.264
1990	6193124.591
1991	6194349.098000001
1992	6185710.545
1993	6180330.173
1994	6168326.800000001
1995	6159529.2
1996	6167164.600000001
1997	6176126.300000001
1998	6189566
1999	6197050.7
2000	6190515.600000001
2001	6164892.9
2002	6168145.2
2003	6171786.4
2004	6181732.4
2005	6194401.4
2006	6194364.9120000005
2007	6207871.7
2008	6156648.800000001
2009	6132865.1
2010	6154365.800000001
2011	6142077.800000001
2012	6150372.4
2013	6151677.500000001
2014	6113898.828
2015	6122025.194
2016	6101636.111
2017	6069955.345000001
2018	6064254.289999999
2019	6072479.426000001
2020	6104985.628000001
2021	6107231.569