Year % of land area 1961 32.65602322206096 1962 32.65602322206096 1963 32.65602322206096 1964 32.65602322206096 1965 32.65602322206096 1966 32.65602322206096 1967 32.65602322206096 1968 32.65602322206096 1969 32.65602322206096 1970 32.65602322206096 1971 32.65602322206096 1972 27.866473149492016 1973 27.866473149492016 1974 27.866473149492016 1975 27.866473149492016 1976 27.939042089985488 1977 27.939042089985488 1978 28.30188679245283 1979 28.30188679245283 1980 28.30188679245283 1981 28.30188679245283 1982 28.30188679245283 1983 28.30188679245283 1984 28.30188679245283 1985 28.30188679245283 1986 28.30188679245283 1987 28.30188679245283 1988 28.30188679245283 1989 28.30188679245283 1990 28.30188679245283 1991 28.30188679245283 1992 28.30188679245283 1993 28.30188679245283 1994 29.027576197387518 1995 29.027576197387518 1996 29.027576197387518 1997 32.65602322206096 1998 32.65602322206096 1999 32.65602322206096 2000 32.65602322206096 2001 32.65602322206096 2002 32.65602322206096 2003 32.65602322206096 2004 32.65602322206096 2005 36.284470246734394 2006 36.284470246734394 2007 36.284470246734394 2008 36.284470246734394 2009 37.239840348330915 2010 42.815674891146585 2011 42.815674891146585 2012 42.815674891146585 2013 42.815674891146585 2014 42.815674891146585 2015 42.815674891146585 2016 42.815674891146585 2017 42.815674891146585 2018 42.815674891146585 2019 36.284470246734394 2020 36.284470246734394 2021 36.46589259796807