Year	% of land area
1961	1.1463076136446642
1962	1.168846979272827
1963	1.2075256437458477
1964	1.2447434234096355
1965	1.2645697172492234
1966	1.281752505243533
1967	1.3079788658664264
1968	1.3207094334897407
1969	1.33072692932448
1970	1.3484662448651639
1971	1.3536836906124239
1972	1.379283957745646
1973	1.403913231609161
1974	1.4343176034694096
1975	1.4713984790006929
1976	1.5030511813762455
1977	1.5205123424669351
1978	1.5420779199096193
1979	1.579156799835267
1980	1.6092790418761773
1981	1.6319576813804195
1982	1.6533841260654092
1983	1.5149289611850518
1984	1.5367224336584655
1985	1.66327530695509
1986	1.7978672709623686
1987	1.9434501793006196
1988	2.052417541667688
1989	2.102391795405715
1990	2.207609675621018
1991	2.2187279204975603
1992	2.239137956562143
1993	2.3492893511999218
1994	2.468169961262245
1995	2.5984190232197966
1996	2.628501945967691
1997	2.659211238801957
1998	2.673404081706955
1999	2.7492039108500204
2000	2.784283114767939
2001	2.861380367710857
2002	2.9239517571947027
2003	3.0100033757263227
2004	3.0730279464660497
2005	3.13688601631849
2006	3.2374089370740458
2007	3.3722355132659105
2008	3.453535049829676
2009	3.5641181355256757
2010	3.6521882751075982
2011	3.7752444234381746
2012	3.8468455338625516
2013	3.9212400663920812
2014	3.966695051542203
2015	4.062085765000734
2016	4.1425430929064495
2017	4.358542645296602
2018	4.4420811728132685
2019	4.535254401326735
2020	4.570390700696991
2021	4.597793947531784