Year	sq. km
1961	17363
1962	17334
1963	17192
1964	17104
1965	17016
1966	16957
1967	16888
1968	16861
1969	16874
1970	16739
1971	16654
1972	16628
1973	16537
1974	16475
1975	16438
1976	16426
1977	16414
1978	16449
1979	16587.287
1980	16533.566000000003
1981	16489.881999999998
1982	16441.394
1983	16393.05
1984	16344.562
1985	16290.524
1986	16248.017
1987	16199.958
1988	16152.041000000001
1989	16104.266000000001
1990	16050.303
1991	16009.14
1992	15961.788
1993	15914.576000000001
1994	15867.503
1995	15820.57
1996	15783.105
1997	15752.201000000001
1998	15721.444
1999	15688.881000000001
2000	15658.165
2001	15627.446000000002
2002	15597.256000000001
2003	15566.688999999998
2004	15535.559
2005	15504.631000000001
2006	15474.187
2007	15443.686000000002
2008	15410.273000000001
2009	15376.983
2010	15344.107
2011	15311.226
2012	15278.375
2013	15245.633
2014	15212.778
2015	15180.055
2016	15147.463
2017	15116.339
2018	15085.726999999999
2019	15055.158000000001
2020	15024.368999999999
2021	14993.783000000001