Year	% of land area
1961	18.181818181818183
1962	15.909090909090908
1963	15.909090909090908
1964	15.909090909090908
1965	13.636363636363635
1966	13.636363636363635
1967	13.636363636363635
1968	13.636363636363635
1969	13.636363636363635
1970	13.636363636363635
1971	13.636363636363635
1972	11.363636363636363
1973	11.363636363636363
1974	11.363636363636363
1975	11.363636363636363
1976	11.363636363636363
1977	11.363636363636363
1978	11.363636363636363
1979	11.363636363636363
1980	11.363636363636363
1981	11.363636363636363
1982	11.363636363636363
1983	11.363636363636363
1984	9.090909090909092
1985	9.090909090909092
1986	9.090909090909092
1987	9.090909090909092
1988	9.090909090909092
1989	9.090909090909092
1990	9.090909090909092
1991	9.090909090909092
1992	9.090909090909092
1993	9.090909090909092
1994	9.090909090909092
1995	9.090909090909092
1996	9.090909090909092
1997	9.090909090909092
1998	9.090909090909092
1999	9.090909090909092
2000	9.090909090909092
2001	9.090909090909092
2002	9.090909090909092
2003	9.090909090909092
2004	9.090909090909092
2005	9.090909090909092
2006	9.090909090909092
2007	9.090909090909092
2008	9.090909090909092
2009	9.090909090909092
2010	9.090909090909092
2011	9.090909090909092
2012	9.090909090909092
2013	9.090909090909092
2014	9.090909090909092
2015	9.090909090909092
2016	9.090909090909092
2017	9.090909090909092
2018	9.090909090909092
2019	9.090909090909092
2020	9.090909090909092
2021	9.090909090909092