Year	sq. km
1961	2891400
1962	2890640
1963	2893660
1964	2894700
1965	2897460
1966	2897720
1967	2904460
1968	2908030
1969	2915340
1970	2923350
1971	2945260
1972	2966120
1973	2971600
1974	2973500
1975	2964350
1976	2967860
1977	2967300
1978	2964620
1979	2976650
1980	2965280
1981	2928996
1982	2937573.4
1983	2946977.4
1984	3005863.6
1985	3061518
1986	3113648
1987	3171840
1988	3231800
1989	3279248
1990	3332592
1991	3353769
1992	3372964.8
1993	3454776.8
1994	3529829.896
1995	3600665.327
1996	3674980.4050000003
1997	3735540.5319999997
1998	3825103.175
1999	3883136.9979999997
2000	3877667.131
2001	3884881.989
2002	3891671.7309999997
2003	3900000.7690000003
2004	3908430.778
2005	3740756.859
2006	3744807.103
2007	3749130.8890000004
2008	3725150.164
2009	3719986
2010	3723734.8
2011	3725587.0640000002
2012	3727289.727
2013	3729739.441
2014	3729396.0549999997
2015	3731310.289
2016	3736990.6959999995
2017	3745781.733
2018	3745577.057
2019	3738062.876
2020	3747193.8729999997
2021	3747214.785