Year	% of land area
1961	3.10791220529515
1962	3.115542104326153
1963	3.121900353518655
1964	3.1282586027111576
1965	3.140975101096162
1966	3.1460617004501636
1967	3.1791245962511763
1968	3.306289580101223
1969	3.43345456395127
1970	3.54154480022381
1971	3.54154480022381
1972	3.560619547801317
1973	3.624202039726341
1974	3.624202039726341
1975	3.64963503649635
1976	3.64963503649635
1977	3.64963503649635
1978	3.64963503649635
1979	3.64963503649635
1980	3.64963503649635
1981	3.713217528421374
1982	3.8149495155014117
1983	3.8149495155014117
1984	3.942114499351459
1985	4.005696991276482
1986	4.069279483201506
1987	4.196444467051553
1988	4.260026958976576
1989	4.3236094509016
1990	4.387191942826623
1991	4.450774434751647
1992	4.476207431521656
1993	4.476207431521656
1994	4.53978992344668
1995	4.641521910526717
1996	4.768686894376764
1997	4.959434370151835
1998	5.086599354001882
1999	5.023016862076859
2000	4.959434370151835
2001	5.086599354001882
2002	5.6588417813270935
2003	5.722424273252117
2004	5.849589257102164
2005	6.3582491925023525
2006	6.231084208652306
2007	6.612579160202446
2008	6.86690912790254
2009	6.994074111752588
2010	7.184821587527658
2011	7.184821587527658
2012	7.184821587527658
2013	7.184821587527658
2014	7.184821587527658
2015	7.184821587527658
2016	7.184821587527658
2017	7.184821587527658
2018	7.184821587527658
2019	7.184821587527658
2020	7.184821587527658
2021	7.184821587527658