Year	% of land area
1961	0.6993006993006993
1962	0.6993006993006993
1963	0.6993006993006993
1964	0.6993006993006993
1965	0.6993006993006993
1966	0.6993006993006993
1967	0.6993006993006993
1968	0.6993006993006993
1969	0.6993006993006993
1970	0.6993006993006993
1971	0.6993006993006993
1972	0.6993006993006993
1973	0.6993006993006993
1974	0.6993006993006993
1975	0.6993006993006993
1976	0.6993006993006993
1977	0.6993006993006993
1978	0.6993006993006993
1979	0.6993006993006993
1980	0.6993006993006993
1981	0.6993006993006993
1982	0.6993006993006993
1983	0.6993006993006993
1984	0.6993006993006993
1985	0.6993006993006993
1986	0.6993006993006993
1987	0.6993006993006993
1988	0.6993006993006993
1989	0.6993006993006993
1990	0.6993006993006993
1991	0.6993006993006993
1992	0.6993006993006993
1993	0.6993006993006993
1994	0.5994005994005994
1995	0.5994005994005994
1996	0.5994005994005994
1997	0.5994005994005994
1998	0.5994005994005994
1999	0.5994005994005994
2000	0.6993006993006993
2001	0.6993006993006993
2002	0.6993006993006993
2003	0.6993006993006993
2004	0.6993006993006993
2005	0.6993006993006993
2006	0.6993006993006993
2007	0.6993006993006993
2008	0.6993006993006993
2009	0.6993006993006993
2010	0.6993006993006993
2011	0.7992007992007992
2012	0.7992007992007992
2013	0.7992007992007992
2014	0.7992007992007992
2015	0.7992007992007992
2016	0.7992007992007992
2017	0.7992007992007992
2018	0.7992007992007992
2019	0.7992007992007992
2020	0.7992007992007992
2021	0.7992007992007992