Year	% of land area
1961	1.9649874955341193
1962	1.9649874955341193
1963	1.9649874955341193
1964	1.9649874955341193
1965	1.9649874955341193
1966	1.9649874955341193
1967	1.9649874955341193
1968	1.9649874955341193
1969	1.9649874955341193
1970	1.9649874955341193
1971	1.9649874955341193
1972	1.9649874955341193
1973	1.9649874955341193
1974	1.9649874955341193
1975	1.9649874955341193
1976	1.9649874955341193
1977	2.000714540907467
1978	2.0364415862808145
1979	2.1078956770275097
1980	2.1078956770275097
1981	2.1078956770275097
1982	2.2150768131475527
1983	2.2150768131475527
1984	2.286530903894248
1985	2.286530903894248
1986	2.3579849946409435
1987	2.3222579492675957
1988	2.393712040014291
1989	2.4294390853876386
1990	2.4294390853876386
1991	2.465166130760986
1992	2.536620221507681
1993	2.536620221507681
1994	2.572347266881029
1995	2.608074312254377
1996	2.608074312254377
1997	2.608074312254377
1998	2.643801357627724
1999	2.7152554483744193
2000	2.7152554483744193
2001	2.750982493747767
2002	2.8224365844944623
2003	2.965344765987853
2004	3.0010718113612005
2005	3.2511611289746343
2006	3.3940693104680246
2007	3.429796355841372
2008	3.536977491961415
2009	3.644158628081458
2010	3.858520900321544
2011	3.965702036441586
2012	4.037156127188282
2013	4.037156127188282
2014	4.090746695248303
2015	4.144337263308325
2016	4.180064308681672
2017	4.287245444801715
2018	4.287245444801715
2019	4.287245444801715
2020	4.287245444801715
2021	4.287245444801715