Year	% of land area
1961	0.5126382751673026
1962	0.5351132301688049
1963	0.5391497520205158
1964	0.5593323612790712
1965	0.5698970851378704
1966	0.5682525762353214
1967	0.5559436762677581
1968	0.5598306973101466
1969	0.571790762055957
1970	0.5794153033314112
1971	0.5882358510814465
1972	0.5954617235320403
1973	0.6101227695662798
1974	0.6254391362348797
1975	0.6429438959400988
1976	0.6472148059942846
1977	0.6680959181611903
1978	0.6788105699890775
1979	0.6904720980250106
1980	0.7022831328306351
1981	0.7127486067090365
1982	0.7254068465429127
1983	0.7349254442132682
1984	0.7543114886832595
1985	0.784063335851858
1986	0.7981169722028542
1987	0.8055923106874266
1988	0.8228354247918405
1989	0.831656324203636
1990	0.8428194963405976
1991	0.8612088290126458
1992	0.8742657535656991
1993	0.8940852376466264
1994	0.9082668347830546
1995	0.9216550558559062
1996	0.9278533063525969
1997	0.9358366529923343
1998	0.9540843024545915
1999	0.9590429028519439
2000	0.9861168610214885
2001	0.9985133620148697
2002	1.0074388427301042
2003	1.023653466029447
2004	1.0429007745338919
2005	1.0605336746948024
2006	1.0697981876360565
2007	1.0829239245919198
2008	1.1032425586655246
2009	1.117003534420031
2010	1.1500786725128371
2011	1.161501978464513
2012	1.1665127371702344
2013	1.1943952099691586
2014	1.2269042551039255
2015	1.2792332581256434
2016	1.2691299350224485
2017	1.2897520177051018
2018	1.357298956314547
2019	1.3683531321142999
2020	1.380523019520197
2021	1.3943102278644919