Year	sq. km
1961	35554
1962	35310
1963	34898
1964	34765
1965	34642
1966	34060
1967	33737
1968	33593
1969	33511
1970	33358
1971	33209
1972	33071
1973	32222
1974	32073
1975	31895
1976	31835
1977	31776
1978	31808
1979	31429
1980	31410
1981	31554
1982	31427
1983	30259
1984	30332
1985	30375
1986	30268
1987	30280
1988	30483
1989	30506
1990	30239
1991	30369
1992	30130
1993	29990
1994	29941
1995	29811
1996	29733
1997	29646
1998	29599
1999	29552
2000	29402
2001	29161
2002	29022
2003	28852.3
2004	28674
2005	28568
2006	28433
2007	28301
2008	28094
2009	27950
2010	27792
2011	27573
2012	27352
2013	27164
2014	27142
2015	27184.5
2016	26701.7
2017	26546.2
2018	26528.3
2019	26512.1
2020	26026.654
2021	25974.593999999997