Year	% of land area
1961	22.727272727272727
1962	20.454545454545457
1963	20.454545454545457
1964	20.454545454545457
1965	20.454545454545457
1966	20.454545454545457
1967	20.454545454545457
1968	20.454545454545457
1969	20.454545454545457
1970	20.454545454545457
1971	22.727272727272727
1972	20.454545454545457
1973	20.454545454545457
1974	20.454545454545457
1975	20.454545454545457
1976	20.454545454545457
1977	20.454545454545457
1978	20.454545454545457
1979	20.454545454545457
1980	20.454545454545457
1981	20.454545454545457
1982	20.454545454545457
1983	20.454545454545457
1984	20.454545454545457
1985	20.454545454545457
1986	20.454545454545457
1987	20.454545454545457
1988	20.454545454545457
1989	20.454545454545457
1990	20.454545454545457
1991	20.454545454545457
1992	20.454545454545457
1993	20.454545454545457
1994	20.454545454545457
1995	20.454545454545457
1996	20.454545454545457
1997	20.454545454545457
1998	20.454545454545457
1999	20.454545454545457
2000	20.454545454545457
2001	20.454545454545457
2002	20.454545454545457
2003	20.454545454545457
2004	20.454545454545457
2005	20.454545454545457
2006	20.454545454545457
2007	20.454545454545457
2008	20.454545454545457
2009	20.454545454545457
2010	20.454545454545457
2011	20.454545454545457
2012	20.454545454545457
2013	20.454545454545457
2014	20.454545454545457
2015	20.454545454545457
2016	20.454545454545457
2017	20.454545454545457
2018	20.454545454545457
2019	20.454545454545457
2020	20.454545454545457
2021	20.454545454545457