Year sq. km 1961 1468.5 1962 1448.5 1963 1438.5 1964 1418.5 1965 1408.5 1966 1388.5 1967 1378.5 1968 1358.5 1969 1348.5 1970 1328.5 1971 1318.5 1972 1298.5 1973 1288.5 1974 1268.5 1975 1258.5 1976 1238.5 1977 1228.5 1978 1208.5 1979 1198.5 1980 1178.5 1981 1168.5 1982 1148.5 1983 1138.5 1984 1078.5 1985 1078.5 1986 1078.5 1987 1078.5 1988 1078.5 1989 1078.5 1990 1038.5 1991 1038.5 1992 1048.5 1993 1028.5 1994 1028.5 1995 1028.5 1996 1038.5 1997 1048.5 1998 1028.5 1999 1028.5 2000 1028.5 2001 1028.5 2002 1028.5 2003 1028.5 2004 1028.5 2005 1029.8 2006 1031.1 2007 1032.4 2008 1033.7 2009 1035 2010 1036.3 2011 1037.6 2012 1038.9 2013 1040.2 2014 1041.5 2015 1042.8 2016 1044.1 2017 1045.4 2018 1046.7 2019 1048 2020 1049.2 2021 1049.2