Year sq. km 1961 5677657 1962 5715237 1963 5748976 1964 5788985 1965 5823254 1966 5855292 1967 5884281 1968 5922130 1969 5947519 1970 5991908 1971 6051037 1972 6108995 1973 6157536.227 1974 6206616.455 1975 6258678.682 1976 6324112.326 1977 6390945.9690000005 1978 6449929.614 1979 6507474.258 1980 6566992.981 1981 6597285.545 1982 6623099.19 1983 6673742.833 1984 6710033.727 1985 6736615.692000001 1986 6737079.515 1987 6738156.009 1988 6735864.302999999 1989 6734452.597 1990 6757071.591 1991 6757214.765000001 1992 6743864.878 1993 6736733.173 1994 6724338.467 1995 6714429.533 1996 6721233.600000001 1997 6730103.967 1998 6743437.333 1999 6749304.700000001 2000 6743966.267000001 2001 6718759.233 2002 6725605.2 2003 6726835.067 2004 6741267.033000001 2005 6753402.4 2006 6750604.012 2007 6762027.600000001 2008 6708780.540000001 2009 6681775.590000001 2010 6696156.920000002 2011 6681118.760000001 2012 6682761.100000001 2013 6681346.950000001 2014 6641036.018 2015 6645256.114000001 2016 6619022.781 2017 6583106.755000001 2018 6573263.44 2019 6577078.306000002 2020 6605191.258000001 2021 6603895.149