Year	sq. km
1961	26460
1962	26580
1963	26700
1964	26820
1965	26940
1966	27060
1967	27280
1968	27400
1969	27420
1970	27550
1971	27670
1972	28000
1973	28430
1974	28750
1975	28880
1976	29300
1977	29930
1978	30050
1979	30160
1980	30500
1981	30670
1982	31040
1983	31190
1984	37850
1985	37850
1986	37850
1987	37850
1988	42850
1989	42850
1990	42850
1991	42850
1992	42850
1993	44820
1994	45120
1995	45120
1996	45120
1997	45744.3
1998	46368.6
1999	46992.9
2000	47617.2
2001	48241.5
2002	48865.8
2003	49490
2004	47230
2005	45620
2006	43154.512
2007	44480
2008	44340
2009	43696
2010	43172
2011	42948
2012	42624
2013	42230
2014	42849
2015	44640
2016	44938
2017	45236
2018	45534
2019	45832
2020	46120
2021	46120