Year	% of land area
1961	0.2606882168925964
1962	0.2670464660850988
1963	0.2734047152776012
1964	0.27721966479310256
1965	0.27721966479310256
1966	0.2797629644701035
1967	0.2797629644701035
1968	0.2797629644701035
1969	0.2848495638241054
1970	0.2848495638241054
1971	0.2848495638241054
1972	0.2899361631781073
1973	0.29247946285510823
1974	0.29247946285510823
1975	0.29247946285510823
1976	0.29247946285510823
1977	0.29247946285510823
1978	0.29247946285510823
1979	0.29247946285510823
1980	0.29247946285510823
1981	0.29247946285510823
1982	0.29247946285510823
1983	0.29247946285510823
1984	0.29247946285510823
1985	0.29247946285510823
1986	0.29247946285510823
1987	0.29247946285510823
1988	0.29247946285510823
1989	0.29247946285510823
1990	0.29247946285510823
1991	0.29247946285510823
1992	0.29247946285510823
1993	0.29247946285510823
1994	0.29247946285510823
1995	0.29247946285510823
1996	0.29883771204761056
1997	0.29883771204761056
1998	0.29883771204761056
1999	0.30519596124011295
2000	0.3179124596251176
2001	0.3179124596251176
2002	0.3179124596251176
2003	0.3179124596251176
2004	0.3179124596251176
2005	0.3179124596251176
2006	0.3179124596251176
2007	0.3179124596251176
2008	0.3179124596251176
2009	0.34334545639512704
2010	0.3814949515501412
2011	0.3814949515501412
2012	0.3814949515501412
2013	0.3814949515501412
2014	0.3814949515501412
2015	0.3814949515501412
2016	0.3814949515501412
2017	0.3814949515501412
2018	0.3814949515501412
2019	0.3814949515501412
2020	0.3814949515501412
2021	0.3814949515501412