Year	sq. km
1961	12241208.8
1962	12237458.8
1963	12221367.8
1964	12210846.8
1965	12204765.8
1966	12204243.8
1967	12201242.8
1968	12204031.8
1969	12183340.8
1970	12189454.8
1971	12195508.8
1972	12240966.8
1973	12262248.026999999
1974	12270049.255
1975	12273500.482
1976	12279931.708999999
1977	12299012.936
1978	12323174.164
1979	12355019.390999999
1980	12352825.618
1981	12318112.845
1982	12342817.473
1983	12351644.7
1984	12447782.127
1985	12542047.754999999
1986	12616243.981999999
1987	12741096.208999999
1988	12810446.436
1989	12895813.664
1990	12988148.590999998
1991	12997010.138
1992	13007099.785
1993	12857856.633
1994	12944263.576
1995	13040461.627
1996	13124608.325000001
1997	13218081.322
1998	13317384.042
1999	13417250.182
2000	13431666.932
2001	13467544.787
2002	13487414.906000001
2003	13494971.231
2004	13534853.277
2005	13380614.005
2006	13393331.478000002
2007	13411399.939000001
2008	13327977.890999999
2009	13311297.663
2010	13324307.513000002
2011	13322571.279000001
2012	13317987.873
2013	13301176.568999998
2014	13273935.052
2015	13284824.167
2016	13282291.389000002
2017	13297240.654000001
2018	13292840.119
2019	13293491.151999999
2020	13331842.438000001
2021	13347985.526