Year	% of land area
1961	9.903002019255753
1962	9.904723969670814
1963	9.905668162989178
1964	9.916499174144544
1965	9.910697321367891
1966	9.896571758995767
1967	9.874583825452492
1968	9.854941819946196
1969	9.829225841605009
1970	9.82204756760353
1971	9.748718805955521
1972	9.775060660430665
1973	9.770513921263912
1974	9.860375375707815
1975	9.794994502011365
1976	9.834282109810987
1977	9.8873428743556
1978	9.910732251831515
1979	9.91928256589503
1980	9.927502536983107
1981	9.988621683007846
1982	10.324217238324419
1983	10.688369741469883
1984	11.118137092742609
1985	11.626284959768183
1986	11.715233919371277
1987	11.791795017395414
1988	11.850060683580585
1989	11.916914001445269
1990	11.976995921154407
1991	11.91113230848406
1992	11.77281766300312
1993	11.663731462369674
1994	11.551772407447253
1995	11.484913042197482
1996	11.52341280917728
1997	11.552334388792353
1998	11.585394402510532
1999	11.661718137884604
2000	11.70196305442352
2001	11.820046121946264
2002	11.885205188199645
2003	11.939197423823746
2004	12.008831486283762
2005	12.024582048587696
2006	12.07252449273789
2007	12.090286237338987
2008	12.125416585818567
2009	12.135556629997554
2010	12.061727538848348
2011	11.989556678287045
2012	11.912024029097548
2013	11.849778585337518
2014	11.791358876840503
2015	11.805795870562653
2016	11.804599707396237
2017	11.780730953170035
2018	11.687414257003066
2019	11.580377017947196
2020	11.576897754655375
2021	11.572244083941206