Year	% of land area
1961	0.7547214698085536
1962	0.771425525927307
1963	0.7982989921960515
1964	0.8245857858809411
1965	0.8388235430565166
1966	0.8512354275015329
1967	0.8694682145891077
1968	0.8798064046560219
1969	0.8872216306492845
1970	0.8986446050079895
1971	0.9023138744496949
1972	0.9186864484854427
1973	0.9344873374952295
1974	0.9545778019757953
1975	0.9779546830214295
1976	0.9970807571124267
1977	1.006758057936965
1978	1.0191887174315717
1979	1.0426488404746648
1980	1.0613865693709246
1981	1.0759974054939803
1982	1.0886122985442535
1983	1.0343170239593604
1984	1.0486464225929726
1985	1.1311303281418172
1986	1.219303080300585
1987	1.313470929930726
1988	1.3878747501301119
1989	1.41811590614173
1990	1.4867928868469817
1991	1.493906751610619
1992	1.5070653773097094
1993	1.5792921782866562
1994	1.6571757118250319
1995	1.742270058066473
1996	1.7617085921559545
1997	1.7819180977614029
1998	1.7916339287485878
1999	1.8417663934735138
2000	1.8674343834525284
2001	1.918734662605789
2002	1.9593433554614073
2003	2.0160515782184363
2004	2.0573019861077797
2005	2.0988619969296645
2006	2.1644072243633943
2007	2.2555144856971148
2008	2.3076213048341545
2009	2.3794208302192588
2010	2.437184485826036
2011	2.5176496837338833
2012	2.5628694250524497
2013	2.612827965685594
2014	2.6404430339634275
2015	2.700872408571248
2016	2.753128762597955
2017	2.8942008935485397
2018	2.948831582456846
2019	3.010042476728771
2020	3.0326852771381163
2021	3.052271409958635