Year	% of land area
1961	0.8897819018423301
1962	0.9149157551450691
1963	0.889098410157954
1964	0.9025818370224642
1965	0.9012769892613826
1966	0.9093235504547192
1967	0.9189856374474904
1968	0.9426903717738067
1969	0.9484068476794976
1970	0.9561116630306462
1971	0.9713970225176025
1972	0.9797542617492919
1973	0.9996385879011358
1974	1.0120669787268652
1975	1.0255200042575436
1976	1.0412756303754853
1977	1.058331971259724
1978	1.0642348943344149
1979	1.0792407461506028
1980	1.105586423873434
1981	1.1225184926929423
1982	1.1213379080780042
1983	1.1382078408651473
1984	1.1413457104995883
1985	1.1653612870087258
1986	1.1990079485344642
1987	1.246821625439461
1988	1.2781071177353232
1989	1.2831618839682295
1990	1.3401499460519433
1991	1.3596616320292092
1992	1.3387340606791671
1993	1.37617827362054
1994	1.425496043750647
1995	1.446622394172857
1996	1.470941385467328
1997	1.4837330722891748
1998	1.498380068637397
1999	1.5542452408213414
2000	1.5747090148959713
2001	1.6191144133372546
2002	1.6535766220789803
2003	1.6829000820988425
2004	1.7239005848245077
2005	1.7661983338991318
2006	1.8342055384041804
2007	1.9045452138980443
2008	1.927449671074276
2009	1.9721012249557075
2010	2.006935840904371
2011	2.0577308643736894
2012	2.0829277073326176
2013	2.125112787293342
2014	2.148004215679125
2015	2.16839229421774
2016	2.192594206572488
2017	2.2835533002809645
2018	2.325641804856919
2019	2.3474102760094393
2020	2.3826382191839235
2021	2.410345418358175