Year	sq. km
1961	17972020
1962	17972020
1963	17972020
1964	17972020
1965	17972020
1966	17972020
1967	17972020
1968	17972020
1969	17972020
1970	17972020
1971	17972020
1972	17972020
1973	17972020
1974	17972020
1975	17972020
1976	17971890
1977	17971890
1978	17971890
1979	17971890
1980	17971890
1981	17971890
1982	17971890
1983	17971890
1984	17971890
1985	17971890
1986	17971890
1987	17971890
1988	17971890
1989	17971890
1990	17971890
1991	17971890
1992	17971890
1993	17971890
1994	17971890
1995	17971890
1996	17971890
1997	17971890
1998	17943410
1999	17943410
2000	17943410
2001	17943410
2002	17942400
2003	17942410
2004	17942420
2005	17942450
2006	17942440
2007	17942450
2008	17942450
2009	17942450
2010	17942450
2011	17942873
2012	17942659
2013	17940230
2014	17940030
2015	17940110
2016	17940050
2017	17939810
2018	17939810
2019	17939031
2020	17939031
2021	17939031