Year sq. km 1961 15922288.742 1962 15922288.742 1963 15922288.742 1964 15922288.742 1965 15922288.742 1966 15922288.742 1967 15922288.742 1968 15922288.742 1969 15922288.742 1970 15922288.742 1971 15922288.742 1972 15922288.742 1973 15922258.742 1974 15922218.742 1975 15922198.742 1976 15922198.742 1977 15922198.742 1978 15922198.742 1979 15922198.742 1980 15922198.742 1981 15922198.742 1982 15922198.742 1983 15922198.742 1984 15922198.742 1985 15922198.742 1986 15922198.742 1987 15922198.742 1988 15922198.742 1989 15922198.742 1990 15922198.742 1991 15923538.742 1992 15923538.742 1993 15923538.742 1994 15923538.742 1995 15923528.742 1996 15923518.742 1997 15923518.742 1998 15923518.742 1999 15923518.742 2000 15975027.742 2001 15975051.942 2002 15974511.168 2003 15981277.758 2004 15980915.519 2005 15983621.891 2006 15986704.493 2007 15986516.893000001 2008 15986546.887 2009 15986507.134 2010 15986826.418 2011 15986805.947 2012 15986838.946 2013 15986320.383 2014 15986683.921 2015 15986698.4 2016 15986401.4 2017 15986337.4 2018 15986313 2019 15986316 2020 15986534.803 2021 16001571.47