Year	sq. km
1961	950
1962	950
1963	950
1964	950
1965	950
1966	950
1967	950
1968	950
1969	950
1970	950
1971	950
1972	950
1973	950
1974	950
1975	950
1976	950
1977	950
1978	1000
1979	1000
1980	1000
1981	1000
1982	1000
1983	1000
1984	1100
1985	1100
1986	1100
1987	1130
1988	1140
1989	1140
1990	1140
1991	1150
1992	1150
1993	1180
1994	1200
1995	1220
1996	1240
1997	1260
1998	1260
1999	1270
2000	1280
2001	1300
2002	1310
2003	1320
2004	1330
2005	1330
2006	1330
2007	1330
2008	1330
2009	1330
2010	1330
2011	1330
2012	1330
2013	1330
2014	1330
2015	1330
2016	1330
2017	1330
2018	1330
2019	1330
2020	1330
2021	1330