Year	% of land area
1961	0.263042525208242
1962	0.263042525208242
1963	0.263042525208242
1964	0.263042525208242
1965	0.263042525208242
1966	0.263042525208242
1967	0.263042525208242
1968	0.263042525208242
1969	0.263042525208242
1970	0.263042525208242
1971	0.263042525208242
1972	0.263042525208242
1973	0.263042525208242
1974	0.263042525208242
1975	0.263042525208242
1976	0.263042525208242
1977	0.263042525208242
1978	0.263042525208242
1979	0.3068829460762823
1980	0.3068829460762823
1981	0.3068829460762823
1982	0.3068829460762823
1983	0.3068829460762823
1984	0.3068829460762823
1985	0.4384042086804033
1986	0.48224462954844366
1987	0.657606313020605
1988	0.7452871547566856
1989	0.8768084173608066
1990	1.0960105217010083
1991	1.183691363437089
1992	1.3590530469092503
1993	1.4905743095133712
1994	1.4905743095133712
1995	1.4905743095133712
1996	1.4905743095133712
1997	1.4905743095133712
1998	1.4905743095133712
1999	1.578255151249452
2000	1.5344147303814117
2001	1.4905743095133712
2002	1.4028934677772906
2003	1.4028934677772906
2004	1.4028934677772906
2005	1.4028934677772906
2006	1.4028934677772906
2007	1.4028934677772906
2008	1.4028934677772906
2009	1.4028934677772906
2010	1.4028934677772906
2011	1.4028934677772906
2012	1.4028934677772906
2013	1.4028934677772906
2014	1.4028934677772906
2015	1.4028934677772906
2016	1.4028934677772906
2017	1.4028934677772906
2018	1.4028934677772906
2019	1.4028934677772906
2020	1.4028934677772906
2021	1.4028934677772906