Year sq. km 1961 22843557.7 1962 22914879.8 1963 22974718 1964 23037208.5 1965 23114901.7 1966 23195977.6 1967 23269312.1 1968 23358677.3 1969 23440022.7 1970 23535532.400000002 1971 23659459.1 1972 23786869.6 1973 23904999.427 1974 24032526.455000002 1975 24125334.382000003 1976 24104953.742 1977 24245259.503000002 1978 24377856.664 1979 24495732.991 1980 24584310.198000003 1981 24634501.245 1982 24758387.873 1983 24919717.599999998 1984 25088169.827000003 1985 25272660.825 1986 25358703.482 1987 25465483.709000003 1988 25538270.936 1989 25615301.164 1990 25708619.091000002 1991 25763460.818000004 1992 25770784.285 1993 25750184.133 1994 25777141.78 1995 25709074.799999997 1996 25701089.02 1997 25837890.04 1998 25858143.46 1999 25883107.679999996 2000 25893548.099999998 2001 25874472.434 2002 25884739.769 2003 25729101.403 2004 25754370.338 2005 25587983.472 2006 25593264.319 2007 25598224.941 2008 25532233.116 2009 25518473.762 2010 25587433.453 2011 25572344.68 2012 25567753.072999995 2013 25573334.378999997 2014 25522088.177999996 2015 25536828.945 2016 25520889.495 2017 25509590.343 2018 25491465.083 2019 25469095.348000005 2020 25493347.401000004 2021 25494462.671