Year	sq. km
1961	20066781
1962	20066781
1963	20066781
1964	20066781
1965	20066781
1966	20066781
1967	20066781
1968	20066781
1969	20066781
1970	20066781
1971	20066781
1972	20066781
1973	20066781
1974	20066381
1975	20065981
1976	20065981
1977	20065981
1978	20065981
1979	20065981
1980	20065981
1981	20065981
1982	20065981
1983	20065981
1984	20065981
1985	20065981
1986	20065981
1987	20065981
1988	20065981
1989	20065981
1990	20065981
1991	20065981
1992	20065981
1993	20166981
1994	20166981
1995	20166981
1996	20166981
1997	20166981
1998	20166981
1999	20166981
2000	20166981
2001	20166981
2002	20166981
2003	20166981
2004	20186963.625
2005	20187006.326
2006	20186985.031
2007	20187013.606
2008	20187038.494
2009	20184000.592
2010	20184706.103
2011	20184984.989
2012	20308908.12
2013	20308688.278
2014	20308675.185
2015	20308727.775
2016	20308716.459
2017	20308710.233
2018	20308716.714
2019	20308719.546
2020	20308679.829
2021	20308679.829