Year	sq. km
1961	100
1962	100
1963	110
1964	110
1965	110
1966	110
1967	110
1968	110
1969	110
1970	110
1971	110
1972	110
1973	100
1974	100
1975	100
1976	100
1977	110
1978	110
1979	120
1980	120
1981	120
1982	110
1983	120
1984	120
1985	120
1986	130
1987	116.6
1988	113
1989	109.4
1990	105.8
1991	102.2
1992	98.6
1993	95
1994	91.4
1995	87.8
1996	84.2
1997	80.6
1998	77
1999	73.4
2000	70
2001	70
2002	70
2003	70
2004	70
2005	70
2006	70
2007	70
2008	70
2009	70
2010	70
2011	70
2012	70
2013	70
2014	70
2015	70
2016	70
2017	70
2018	70
2019	70
2020	70
2021	70