Year	% of land area
1961	9.19718067732508
1962	9.203320317296594
1963	9.209459957268106
1964	9.215599597239619
1965	9.22173923721113
1966	9.227878877182642
1967	9.240158157125666
1968	9.270856356983225
1969	9.283135636926252
1970	9.301554556840786
1971	9.566173039612957
1972	9.962793781772637
1973	10.376605515852551
1974	10.05059063336526
1975	9.731329354846633
1976	9.412068076328003
1977	9.190427073356418
1978	8.71337704756993
1979	9.32856897271544
1980	7.969866647019819
1981	8.319212161398855
1982	8.682064883715219
1983	8.841081558977383
1984	8.994572558265183
1985	9.148063557552986
1986	9.301554556840786
1987	9.455045556128589
1988	9.565559075615807
1989	9.455045556128589
1990	9.326113116726836
1991	10.241533436479285
1992	10.418355067658833
1993	10.64122399862472
1994	10.644293818610477
1995	10.67560598246519
1996	10.496942459294187
1997	10.131633880989218
1998	10.337311820034873
1999	10.030329821459269
2000	9.162798693484614
2001	9.738082958815294
2002	9.841228910336698
2003	9.944374861858101
2004	10.047520813379505
2005	10.150666764900906
2006	10.253812716422308
2007	10.356958667943712
2008	9.544070335715514
2009	9.556963579655688
2010	9.448905916157077
2011	9.340848252658464
2012	9.232790589159851
2013	9.017289226159777
2014	9.017289226159777
2015	9.017289226159777
2016	9.017289226159777
2017	9.327580893682589
2018	9.603081664098614
2019	9.62732406779661
2020	9.651566533127887
2021	9.675808936825886