Year	% of land area
1961	0.35727045373347627
1962	0.35727045373347627
1963	0.35727045373347627
1964	0.35727045373347627
1965	0.35727045373347627
1966	0.35727045373347627
1967	0.35727045373347627
1968	0.35727045373347627
1969	0.35727045373347627
1970	0.35727045373347627
1971	0.35727045373347627
1972	0.35727045373347627
1973	0.35727045373347627
1974	0.35727045373347627
1975	0.35727045373347627
1976	0.35727045373347627
1977	0.3929974991068239
1978	0.4287245444801715
1979	0.4287245444801715
1980	0.4287245444801715
1981	0.4287245444801715
1982	0.4644515898535191
1983	0.4644515898535191
1984	0.4644515898535191
1985	0.4644515898535191
1986	0.4644515898535191
1987	0.35727045373347627
1988	0.35727045373347627
1989	0.3929974991068239
1990	0.3929974991068239
1991	0.3929974991068239
1992	0.3929974991068239
1993	0.3929974991068239
1994	0.3929974991068239
1995	0.4287245444801715
1996	0.4287245444801715
1997	0.4287245444801715
1998	0.4644515898535191
1999	0.5001786352268668
2000	0.5001786352268668
2001	0.5359056806002144
2002	0.5359056806002144
2003	0.571632725973562
2004	0.6073597713469097
2005	0.6430868167202572
2006	0.6073597713469097
2007	0.6430868167202572
2008	0.6788138620936048
2009	0.6788138620936048
2010	0.7145409074669525
2011	0.7145409074669525
2012	0.7859949982136478
2013	0.7859949982136478
2014	0.8217220435869954
2015	0.8217220435869954
2016	0.8217220435869954
2017	0.8217220435869954
2018	0.8217220435869954
2019	0.8217220435869954
2020	0.8217220435869954
2021	0.8217220435869954