Year	sq. km
1961	5695405.4
1962	5728347.5
1963	5763306.7
1964	5799008.2
1965	5840511.4
1966	5880499.3
1967	5922084.8
1968	5961551
1969	6008627.4
1970	6060583.1
1971	6099205.8
1972	6157208.3
1973	6220286.9
1974	6299202.7
1975	6353569.4
1976	6271317.533000001
1977	6345372.067
1978	6412108
1979	6452739.1
1980	6504248
1981	6562695.9
1982	6665295.9
1983	6776368.4
1984	6882669.2
1985	7036915.5
1986	7122561
1987	7213839
1988	7288916
1989	7363117
1990	7435414
1991	7464248
1992	7467440
1993	7469331
1994	7511848
1995	7522551
1996	7530494
1997	7645854.5
1998	7655039
1999	7691815.5
2000	7714858
2001	7742749.444
2002	7763755.8889999995
2003	7628493.733000001
2004	7649703.778
2005	7662163.322
2006	7694123.666999999
2007	7717887.1110000005
2008	7734912.556
2009	7751493.562
2010	7753009.3
2011	7759877.938
2012	7757546.255
2013	7759388.6959999995
2014	7753561.761
2015	7770645.279
2016	7782127.799999999
2017	7813567.2190000005
2018	7811699.5030000005
2019	7808969.458
2020	7807223.443
2021	7812828.4969999995