Year	sq. km
1961	6170420
1962	6167940
1963	6173000
1964	6170130
1965	6167390
1966	6170970
1967	6172710
1968	6177330
1969	6184480
1970	6194850
1971	6210660
1972	6215230
1973	6217600
1974	6219320
1975	6223940
1976	6223480
1977	6226610
1978	6238150
1979	6234230
1980	6233230
1981	6245830
1982	6248260
1983	6252220
1984	6253050
1985	6294600
1986	6331860
1987	6355170
1988	6390390
1989	6418960
1990	6412859.9
1991	6425829.9
1992	6452049.9
1993	6310879.9
1994	6338889.9
1995	6365919.9
1996	6384059.9
1997	6405880
1998	6426120
1999	6453940
2000	6476930
2001	6491225.859999999
2002	6504191.72
2003	6546767.58
2004	6569764.4399999995
2005	6588991.3
2006	6613485.66
2007	6636990.02
2008	6652183.38
2009	6690576.74
2010	6717045.033
2011	6747104.88
2012	6789159.825
2013	6806324.255
2014	6825399.195
2015	6836525.8
2016	6851382.225
2017	6868999.45
2018	6882362.22
2019	6891016.22
2020	6898158.22
2021	6900855.82