Year	% of land area
1961	0.9415134078921533
1962	0.9666390702544344
1963	0.9613522868044537
1964	0.9753846645716906
1965	0.9811015592176019
1966	0.9851696942791125
1967	0.9879295744530007
1968	1.0026788042134553
1969	1.0168724736791661
1970	1.030062550354372
1971	1.046603910097871
1972	1.0599552784715511
1973	1.0794550068536513
1974	1.0952193870709825
1975	1.1082736848360755
1976	1.1270220338390127
1977	1.148939885658707
1978	1.1669508759111948
1979	1.19215730157301
1980	1.2200877775018681
1981	1.2368711529958532
1982	1.2446938368219338
1983	1.230524103843864
1984	1.2468545981045935
1985	1.2877026309991575
1986	1.3336058804299582
1987	1.3889595424230676
1988	1.427667086080574
1989	1.4449383493379575
1990	1.480826201674631
1991	1.4984646638368488
1992	1.1688881064282812
1993	1.203744672747679
1994	1.2405715955843193
1995	1.2573268209311377
1996	1.272216062869848
1997	1.2877525427037961
1998	1.3028907442624607
1999	1.3320240383639317
2000	1.3520015580979394
2001	1.3802896749000568
2002	1.3999545954392474
2003	1.42695870160355
2004	1.4628381848826473
2005	1.4999564213872403
2006	1.5377628870192384
2007	1.5751054096641237
2008	1.5965042153447953
2009	1.6235706180676102
2010	1.6545486615035612
2011	1.6867941954977757
2012	1.7074199686610714
2013	1.7332769307701819
2014	1.7468645546576032
2015	1.7809232854272419
2016	1.7929867435360116
2017	1.8417544956660852
2018	1.8854882672190023
2019	1.9106369987744716
2020	1.924250565078113
2021	1.9416440641009958