Year	% of land area
1961	11.573867190991152
1962	11.663240682813477
1963	11.707927428724641
1964	11.734739476271336
1965	11.7794262221825
1966	11.833050317275896
1967	11.886674412369292
1968	11.904549110733756
1969	11.868799714004826
1970	11.886674412369292
1971	11.91348645991599
1972	12.226293681294129
1973	12.315667173116454
1974	12.36929126820985
1975	12.628474394494592
1976	12.851908124050407
1977	13.432835820895523
1978	13.441773170077756
1979	13.35239967825543
1980	13.263026186433105
1981	13.236214138886407
1982	13.191527392975244
1983	13.11109125033515
1984	13.084279202788455
1985	13.003843060148359
1986	12.968093663419431
1987	12.878720171597106
1988	12.789346679774779
1989	12.923406917508268
1990	13.066404504423987
1991	13.334524979890963
1992	13.540084011082312
1993	15.04155867369738
1994	14.746626150683706
1995	14.299758691572078
1996	14.299758691572078
1997	13.584770756993475
1998	13.584770756993475
1999	13.120028599517383
2000	9.545088926624363
2001	9.545088926624363
2002	9.545088926624363
2003	9.545088926624363
2004	9.384216641344176
2005	9.384216641344176
2006	9.384216641344176
2007	9.384216641344176
2008	9.098221467512737
2009	9.098221467512737
2010	9.098221467512737
2011	9.098221467512737
2012	9.098221467512737
2013	9.098221467512737
2014	9.098221467512737
2015	9.098221467512737
2016	9.098221467512737
2017	9.098221467512737
2018	9.098221467512737
2019	9.098221467512737
2020	9.098221467512737
2021	9.098221467512737