Year	sq. km
1961	140
1962	140
1963	140
1964	130
1965	130
1966	130
1967	130
1968	130
1969	130
1970	130
1971	120
1972	120
1973	120
1974	120
1975	100
1976	100
1977	90
1978	80
1979	80
1980	90
1981	90
1982	90
1983	90
1984	90
1985	90
1986	90
1987	90
1988	90
1989	80
1990	80
1991	80
1992	80
1993	80
1994	80
1995	80
1996	80
1997	70
1998	70
1999	70
2000	70
2001	70
2002	70
2003	70
2004	70
2005	70
2006	60
2007	60
2008	60
2009	60
2010	55
2011	55
2012	51
2013	51
2014	51
2015	51
2016	50
2017	51
2018	50
2019	50
2020	40
2021	40