Year sq. km 1961 39528 1962 39528 1963 39528 1964 39528 1965 39528 1966 39528 1967 39528 1968 39528 1969 39528 1970 39528 1971 39528 1972 39528 1973 39528 1974 39528 1975 39528 1976 39528 1977 39528 1978 39528 1979 39528.71 1980 39528.71 1981 39528.71 1982 39528.71 1983 39528.71 1984 39528.79 1985 39528.87 1986 39528.95 1987 39529.03 1988 39529.11 1989 39529.19 1990 39529.27 1991 39529.35 1992 39529.43 1993 39529.51 1994 39529.59 1995 39529.67 1996 39528.454 1997 39527.237 1998 39526.019 1999 39524.8 2000 39523.581 2001 39522.36 2002 39521.138999999996 2003 39519.917 2004 39518.693999999996 2005 39517.47 2006 39516.245 2007 39515.02 2008 39514.422 2009 39513.824 2010 39513.225 2011 39512.626000000004 2012 39512.028 2013 39511.428 2014 39510.829 2015 39510.23 2016 39509.63 2017 39509.63 2018 39509.63 2019 39509.63 2020 39509.63 2021 39509.63