Year	sq. km
1961	13611451
1962	13611451
1963	13611451
1964	13611451
1965	13611451
1966	13611451
1967	13611451
1968	13611451
1969	13611451
1970	13611451
1971	13611451
1972	13611451
1973	13611411
1974	13611411
1975	13611411
1976	13611411
1977	13611411
1978	13611411
1979	13611411
1980	13611411
1981	13611411
1982	13611411
1983	13611411
1984	13611411
1985	13611411
1986	13611411
1987	13611411
1988	13611411
1989	13611411
1990	13611411
1991	13611411
1992	13611431
1993	13611431
1994	13611431
1995	13611431
1996	13611431
1997	13611431
1998	13611431
1999	13611431
2000	13611431
2001	13611431
2002	13611431
2003	13611251
2004	13611241
2005	13611251
2006	13611311
2007	13611331
2008	13611341
2009	13608831
2010	13608823
2011	13608828
2012	13100831
2013	13100639
2014	13100520
2015	13100528
2016	13100529
2017	13100530
2018	13100528
2019	13100544
2020	13100549
2021	13100559