Year	sq. km
1961	19.3
1962	19.3
1963	19.3
1964	19.3
1965	19.3
1966	19.3
1967	19.3
1968	19.3
1969	19.3
1970	19.3
1971	19.3
1972	19.3
1973	19.3
1974	19.3
1975	19.3
1976	19.3
1977	19.3
1978	19.3
1979	19.3
1980	19.3
1981	19.3
1982	19.3
1983	19.3
1984	19.3
1985	19.3
1986	19.3
1987	19.3
1988	19.3
1989	19.3
1990	19.3
1991	19.64
1992	19.98
1993	20.32
1994	20.66
1995	21
1996	21.34
1997	21.68
1998	22.02
1999	22.36
2000	22.7
2001	23
2002	23.3
2003	23.6
2004	23.9
2005	24.2
2006	24.5
2007	24.8
2008	25.1
2009	25.4
2010	25.7
2011	26
2012	26.3
2013	26.6
2014	26.9
2015	27.2
2016	27.5
2017	27.8
2018	28.1
2019	28.4
2020	28.7
2021	29