Year	% of land area
1961	8.559082599301977
1962	8.559082599301977
1963	8.559082599301977
1964	8.559082599301977
1965	8.559082599301977
1966	8.642180488615589
1967	8.642180488615589
1968	8.642180488615589
1969	8.642180488615589
1970	8.642180488615589
1971	8.642180488615589
1972	8.642180488615589
1973	8.7252783779292
1974	8.808376267242812
1975	8.808376267242812
1976	8.808376267242812
1977	8.808376267242812
1978	8.849925211899617
1979	8.883164367625064
1980	8.891474156556423
1981	9.556257271065315
1982	9.556257271065315
1983	9.556257271065315
1984	9.971746717633371
1985	10.137942496260594
1986	10.137942496260594
1987	10.387236164201429
1988	10.636529832142264
1989	10.802725610769487
1990	10.802725610769487
1991	10.802725610769487
1992	10.968921389396709
1993	11.218215057337543
1994	11.218215057337543
1995	13.711151736745887
1996	13.711151736745887
1997	14.542130629882
1998	14.957620076450059
1999	15.373109523018117
2000	15.929865381419312
2001	15.888316436762507
2002	15.963104537144757
2003	16.04620242645837
2004	16.104370948977895
2005	16.15422968256606
2006	15.522685723782617
2007	14.874522187136446
2008	14.226358650490278
2009	13.578195113844108
2010	12.921721788266577
2011	12.4896127638358
2012	12.4896127638358
2013	12.4896127638358
2014	12.4896127638358
2015	12.4896127638358
2016	12.4896127638358
2017	12.4896127638358
2018	12.4896127638358
2019	12.4896127638358
2020	12.4896127638358
2021	12.4896127638358