Year	sq. km
1961	30270187.7
1962	30270167.7
1963	30270177.7
1964	30270177.7
1965	30270167.7
1966	30270157.7
1967	30270147.7
1968	30270137.7
1969	30270137.7
1970	30270127.7
1971	30270117.7
1972	30270017.7
1973	30270017.7
1974	30269987.7
1975	30269757.7
1976	30269677.7
1977	30269547.7
1978	30269547.7
1979	30269508.41
1980	30269328.41
1981	30269408.41
1982	30269188.41
1983	30269148.41
1984	30267658.49
1985	30267558.57
1986	30267658.65
1987	30267558.73
1988	30267548.81
1989	30267548.89
1990	30267548.97
1991	30267549.05
1992	31239757.13
1993	31316971.21
1994	31316947.29
1995	31316987.37
1996	31316932.154
1997	31316831.937
1998	31316704.719
1999	31316669.5
2000	31353456.741
2001	31353207.52
2002	31350877.299
2003	31351347.077
2004	31350977.854
2005	31350824.63
2006	31350250.005000003
2007	31350307.38
2008	31335323.982
2009	31336189.284
2010	31337635.285000004
2011	31337896.686
2012	31338102.788
2013	31335989.048
2014	31336539.889000002
2015	31336096.63
2016	31346159.56
2017	31345929.580000006
2018	31346074.108999997
2019	31346071.115999997
2020	31345264.697
2021	31168492.403999995