Year % of land area 1961 69.98597251888928 1962 69.99394267861128 1963 70.00191283833328 1964 70.00988299805529 1965 70.01785315777728 1966 70.02582331749927 1967 70.03379347722128 1968 70.04176363694329 1969 70.04973379666528 1970 70.05770395638729 1971 70.06567411610929 1972 70.0736442758313 1973 70.08161443555329 1974 70.08958459527528 1975 70.09755475499729 1976 70.10552491471928 1977 70.11349507444129 1978 70.1214652341633 1979 70.1294353938853 1980 70.1374055536073 1981 70.1453757133293 1982 70.1533458730513 1983 70.1613160327733 1984 70.16928619249529 1985 70.1772563522173 1986 70.1852265119393 1987 70.1931966716613 1988 70.1995727994389 1989 70.2011668313833 1990 70.2043548952721 1991 70.2043548952721 1992 70.2059489272165 1993 70.2075429591609 1994 70.2171071508273 1995 70.2266713424937 1996 70.2346415022157 1997 70.2426116619377 1998 70.2442056938821 1999 70.2442056938821 2000 70.2442056938821 2001 70.25058182165971 2002 70.2808684286033 2003 70.31115503554692 2004 70.38766856887813 2005 70.33825357860172 2006 70.25855198138171 2007 70.17885038416169 2008 70.33825357860172 2009 70.33825357860172 2010 70.33825357860172 2011 70.17885038416169 2012 70.17885038416169 2013 70.33825357860172 2014 70.33825357860172 2015 70.33825357860172 2016 70.33825357860172 2017 70.33825357860172 2018 70.33825357860172 2019 70.33984761054612 2020 70.34144164249052 2021 70.34303567443492