Year	sq. km
1961	35530
1962	35530
1963	35630
1964	35530
1965	35530
1966	35530
1967	35670
1968	35670
1969	35670
1970	37020
1971	37020
1972	38220
1973	39530
1974	39940
1975	40090
1976	40250
1977	40400
1978	40550
1979	40700
1980	40850
1981	41030
1982	41066
1983	41102
1984	41138
1985	41164
1986	41320
1987	41346
1988	41382
1989	41408
1990	41444
1991	41470
1992	41582
1993	41694
1994	41806
1995	41918
1996	42030
1997	42142
1998	42254
1999	42366
2000	42491
2001	42590
2002	42410
2003	42270
2004	42180
2005	42020
2006	41850
2007	41660
2008	41520
2009	41400
2010	41260
2011	41266
2012	41210
2013	41210
2014	41210
2015	41210
2016	41210
2017	41210
2018	41210
2019	41210
2020	41210
2021	41210