Year	% of land area
1961	0.6364022061943148
1962	0.6364022061943148
1963	0.6364022061943148
1964	0.6364022061943148
1965	0.6682223165040305
1966	0.6682223165040305
1967	0.6894357233771744
1968	0.7106491302503182
1969	0.7106491302503182
1970	0.7106491302503182
1971	0.7106491302503182
1972	0.7106491302503182
1973	0.7106491302503182
1974	0.7424692405600339
1975	0.7424692405600339
1976	0.7636826474331778
1977	0.7955027577428935
1978	0.8273228680526092
1979	0.8485362749257531
1980	0.9546033092914722
1981	0.9546033092914722
1982	0.9546033092914722
1983	1.0606703436571912
1984	1.0606703436571912
1985	1.21977089520577
1986	1.21977089520577
1987	1.2728044123886295
1988	1.3258379295714893
1989	1.3258379295714893
1990	1.3576580398812048
1991	1.3788714467543488
1992	1.3788714467543488
1993	1.3788714467543488
1994	1.3788714467543488
1995	1.3788714467543488
1996	1.3788714467543488
1997	1.3788714467543488
1998	1.3788714467543488
1999	1.3788714467543488
2000	1.3788714467543488
2001	1.3788714467543488
2002	1.3788714467543488
2003	1.3788714467543488
2004	1.3788714467543488
2005	1.3788714467543488
2006	1.4319049639372083
2007	1.4319049639372083
2008	1.4319049639372083
2009	1.4319049639372083
2010	1.4319049639372083
2011	1.4319049639372083
2012	1.4319049639372083
2013	1.591005515485787
2014	2.1213406873143823
2015	2.1213406873143823
2016	2.1213406873143823
2017	2.1213406873143823
2018	2.1213406873143823
2019	2.1213406873143823
2020	2.1213406873143823
2021	2.1213406873143823