Year	sq. km
1961	5635470
1962	5670650
1963	5701999
1964	5735018
1965	5771117
1966	5803795
1967	5831814
1968	5868623
1969	5893872
1970	5935591
1971	5994430
1972	6047458
1973	6093529.227
1974	6144789.455
1975	6195071.682
1976	6258625.326
1977	6325068.969
1978	6384912.614
1979	6443407.258
1980	6502275.981
1981	6532638.545
1982	6557002.19
1983	6606705.833
1984	6643386.727
1985	6669218.692000001
1986	6667372.515
1987	6665709.009
1988	6662807.303
1989	6661675.597
1990	6684774.591
1991	6684927.765000001
1992	6671477.878
1993	6665786.173
1994	6653871.467000001
1995	6643992.533
1996	6651486.600000001
1997	6659816.967
1998	6673465.333
1999	6679628.7
2000	6675467.267000001
2001	6649365.233
2002	6656378.2
2003	6657832.067000001
2004	6673440.033
2005	6684551.4
2006	6681909.012
2007	6693500.600000001
2008	6640766.540000001
2009	6614277.590000001
2010	6629168.920000002
2011	6614648.760000001
2012	6616310.100000001
2013	6615579.950000001
2014	6575954.217999999
2015	6580616.114
2016	6554574.781
2017	6517971.755000001
2018	6508184.44
2019	6510989.306000001
2020	6539102.258000001
2021	6537806.149