Year	% of land area
1961	7.673860911270983
1962	7.673860911270983
1963	7.913669064748201
1964	8.057553956834532
1965	8.15347721822542
1966	8.15347721822542
1967	8.201438848920864
1968	8.201438848920864
1969	8.249400479616307
1970	8.393285371702639
1971	8.633093525179856
1972	8.776978417266188
1973	9.112709832134293
1974	9.59232613908873
1975	10.071942446043165
1976	10.376447876447877
1977	10.81081081081081
1978	10.85907335907336
1979	11.1003861003861
1980	11.67953667953668
1981	11.776061776061777
1982	12.162162162162163
1983	12.403474903474903
1984	12.403474903474903
1985	12.403474903474903
1986	12.403474903474903
1987	12.403474903474903
1988	12.403474903474903
1989	12.403474903474903
1990	12.548262548262548
1991	12.693050193050192
1992	12.693050193050192
1993	12.78957528957529
1994	13.030888030888029
1995	13.175675675675674
1996	12.113899613899614
1997	12.113899613899614
1998	12.065637065637064
1999	12.065637065637064
2000	12.065637065637064
2001	12.065637065637064
2002	11.824324324324325
2003	11.824324324324325
2004	13.513513513513514
2005	10.955598455598455
2006	11.293436293436294
2007	11.438223938223938
2008	11.1003861003861
2009	10.762548262548261
2010	10.424710424710424
2011	10.086872586872587
2012	9.749034749034749
2013	9.411196911196912
2014	9.073359073359073
2015	8.735521235521237
2016	8.397683397683398
2017	8.059845559845561
2018	7.722007722007722
2019	7.722007722007722
2020	7.722007722007722
2021	7.722007722007722