Year	% of land area
1961	11.25
1962	11.25
1963	11.25
1964	11.25
1965	11.25
1966	11.25
1967	11.25
1968	11.25
1969	11.25
1970	11.25
1971	11.25
1972	11.25
1973	11.25
1974	11.25
1975	11.25
1976	11.25
1977	11.25
1978	11.25
1979	11.25
1980	11.25
1981	11.25
1982	11.25
1983	11.25
1984	11.25
1985	11.25
1986	11.25
1987	11.25
1988	11.25
1989	11.25
1990	11.25
1991	11.25
1992	11.25
1993	11.25
1994	11.25
1995	11.25
1996	11.25
1997	11.25
1998	11.25
1999	11.25
2000	11.25
2001	11.25
2002	11.25
2003	11.25
2004	11.25
2005	11.25
2006	11.25
2007	11.25
2008	11.25
2009	11.25
2010	11.25
2011	11.25
2012	11.25
2013	11.25
2014	11.25
2015	11.25
2016	11.25
2017	11.25
2018	11.25
2019	11.25
2020	11.25
2021	11.25