Year	sq. km
1961	35180
1962	35330
1963	35420
1964	35950
1965	36270
1966	36270
1967	36290
1968	35770
1969	34770
1970	34190
1971	24500
1972	24500
1973	24500
1974	25000
1975	25000
1976	25500
1977	25500
1978	26000
1979	26000
1980	26500
1981	26500
1982	26800
1983	26900
1984	26910
1985	29900
1986	32900
1987	37000
1988	41500
1989	44350
1990	44550
1991	45100
1992	45150
1993	45310
1994	45700
1995	45700
1996	45800
1997	45800
1998	46300
1999	46400
2000	47700
2001	48900
2002	50000
2003	51000
2004	52300
2005	53560
2006	53550
2007	53550
2008	53550
2009	53550
2010	54030
2011	54506.937999999995
2012	55323.722
2013	55721.242
2014	56018.761
2015	56476.28
2016	57003.8
2017	57841.319
2018	58558.837999999996
2019	59506.358
2020	60453.877
2021	60991.397000000004