Year	% of land area
1961	0.2286393671262318
1962	0.2400713354825434
1963	0.25150330383885494
1964	0.26293527219516655
1965	0.27436724055147815
1966	0.28579920890778976
1967	0.2972311772641013
1968	0.30866314562041297
1969	0.3200951139767245
1970	0.33152708233303607
1971	0.34524544436061
1972	0.3658229874019709
1973	0.38868692411459405
1974	0.41155086082721726
1975	0.4229828291835288
1976	0.4229828291835288
1977	0.4229828291835288
1978	0.4321284038685781
1979	0.4321284038685781
1980	0.4321284038685781
1981	0.4321284038685781
1982	0.4572787342524636
1983	0.4572787342524636
1984	0.4572787342524636
1985	0.49157463932139833
1986	0.5258705443903331
1987	0.5258705443903331
1988	0.5258705443903331
1989	0.5258705443903331
1990	0.5258705443903331
1991	0.5258705443903331
1992	0.5715984178155795
1993	0.6173262912408259
1994	0.6859181013786954
1995	0.6859181013786954
1996	0.6859181013786954
1997	0.5944623545282026
1998	0.5715984178155795
1999	0.4572787342524636
2000	0.4572787342524636
2001	0.4344147975398404
2002	0.4344147975398404
2003	0.4344147975398404
2004	0.4344147975398404
2005	0.4344147975398404
2006	0.4344147975398404
2007	0.4344147975398404
2008	0.4344147975398404
2009	0.46048996131884323
2010	0.5065389574507276
2011	0.575612451648554
2012	0.575612451648554
2013	0.6910404304721188
2014	0.6910404304721188
2015	0.6910404304721188
2016	0.783179154535068
2017	0.8292485165665426
2018	0.8753178785980172
2019	0.9213872406294917
2020	1.082630007739653
2021	1.082630007739653