Year	% of land area
1961	0.5665080444142306
1962	0.5835032857466577
1963	0.6344890097439384
1964	0.6514842510763652
1965	0.832766825288919
1966	0.832766825288919
1967	0.832766825288919
1968	0.832766825288919
1969	0.832766825288919
1970	0.8271017448447768
1971	0.39655563108996145
1972	0.39655563108996145
1973	0.39655563108996145
1974	0.39655563108996145
1975	0.39655563108996145
1976	0.39655563108996145
1977	0.39655563108996145
1978	0.39655563108996145
1979	0.39655563108996145
1980	0.39655563108996145
1981	0.39655563108996145
1982	0.39655563108996145
1983	0.39655563108996145
1984	0.39655563108996145
1985	0.5098572399728076
1986	0.5098572399728076
1987	0.5665080444142306
1988	0.5665080444142306
1989	0.5665080444142306
1990	0.6231588488556538
1991	0.6231588488556538
1992	0.6514842510763652
1993	0.6514842510763652
1994	0.6798096532970768
1995	0.6798096532970768
1996	0.7364604577384999
1997	0.7364604577384999
1998	0.7364604577384999
1999	0.7931112621799229
2000	0.7931112621799229
2001	0.7931112621799229
2002	0.849762066621346
2003	0.849762066621346
2004	0.849762066621346
2005	0.8837525492861998
2006	0.8780874688420575
2007	0.8780874688420575
2008	0.8780874688420575
2009	0.8780874688420575
2010	0.8780874688420575
2011	0.8780874688420575
2012	1.0197144799456153
2013	1.0763652843870384
2014	1.0763652843870384
2015	1.1670065714933153
2016	1.2973034217085881
2017	1.603217765692273
2018	1.8411511443462498
2019	2.2093813732155
2020	2.5776116020847497
2021	2.713573532744165