Year	% of land area
1961	56.12597066436583
1962	56.12597066436583
1963	56.12597066436583
1964	56.12597066436583
1965	56.12597066436583
1966	56.12597066436583
1967	56.12597066436583
1968	56.12597066436583
1969	56.12597066436583
1970	56.12597066436583
1971	56.12597066436583
1972	56.12597066436583
1973	56.12597066436583
1974	56.12597066436583
1975	56.12597066436583
1976	56.12597066436583
1977	56.12597066436583
1978	56.12597066436583
1979	56.12597066436583
1980	56.12597066436583
1981	56.12597066436583
1982	56.12597066436583
1983	56.12597066436583
1984	56.12597066436583
1985	56.12597066436583
1986	56.12597066436583
1987	56.12597066436583
1988	56.12597066436583
1989	56.12597066436583
1990	56.03968938740294
1991	57.65746333045729
1992	59.167385677308026
1993	60.461604831751515
1994	60.461604831751515
1995	62.62295081967213
1996	63.917169974115616
1997	64.77998274374461
1998	64.77998274374461
1999	66.93701466781708
2000	69.09404659188955
2001	72.54529767040552
2002	73.40811044003452
2003	73.41242450388266
2004	73.41242450388266
2005	73.41242450388266
2006	73.4253666954271
2007	73.43399482312338
2008	73.42105263157895
2009	73.4253666954271
2010	73.43830888697153
2011	73.45987920621225
2012	73.45987920621225
2013	73.45987920621225
2014	73.45987920621225
2015	73.45987920621225
2016	73.45987920621225
2017	73.45987920621225
2018	73.45987920621225
2019	73.46419327006039
2020	73.50733390854185
2021	73.50733390854185