Year	sq. km
1961	6503981.7
1962	6517701.7
1963	6528781.7
1964	6535661.7
1965	6541341.7
1966	6544231.7
1967	6550891.7
1968	6565901.7
1969	6580751.7
1970	6580411.7
1971	6590951.7
1972	6608041.7
1973	6612513.7
1974	6612784.7
1975	6618224.7
1976	6631361.7
1977	6636491.7
1978	6643141.7
1979	6655151.7
1980	6669671.7
1981	6669001.7
1982	6674651.7
1983	6683501.7
1984	6684801.7
1985	6712561.7
1986	6752911.7
1987	6771021.7
1988	6808781.7
1989	6823851.7
1990	6848641.7
1991	6873754.5
1992	6905584.5
1993	6773314.5
1994	6815662.796
1995	6864138.277
1996	6895233.205
1997	6915073.182
1998	6926193.274999999
1999	6942857.748
2000	6964093.331
2001	6993303.599
2002	7011898.650999999
2003	7063912.099
2004	7080765.418
2005	7154411.909
2006	7183320.463
2007	7216817.659
2008	7216976.244
2009	7243603.79
2010	7284048.3
2011	7320498.384
2012	7374615.892000001
2013	7409326.101
2014	7432586.71
2015	7447901.217
2016	7471317.466999999
2017	7495474.705
2018	7511377.109
2019	7518290.433
2020	7530273.216
2021	7536835.58