Year	% of land area
1961	1.5226939970717424
1962	1.5226939970717424
1963	1.5226939970717424
1964	1.5168374816983894
1965	1.5168374816983894
1966	1.5168374816983894
1967	1.5168374816983894
1968	1.5168374816983894
1969	1.5197657393850659
1970	1.5226939970717424
1971	1.5226939970717424
1972	1.5226939970717424
1973	1.534407027818448
1974	1.540263543191801
1975	1.5431918008784773
1976	1.554904831625183
1977	1.5461200585651538
1978	1.4143484626647145
1979	1.4202049780380672
1980	1.4289897510980967
1981	1.437774524158126
1982	1.5109809663250366
1983	1.5226939970717424
1984	1.528550512445095
1985	1.5461200585651538
1986	1.5373352855051245
1987	1.4582723279648608
1988	1.4641288433382138
1989	1.4699853587115665
1990	1.4026354319180088
1991	1.4084919472913615
1992	1.4055636896046853
1993	1.4202049780380672
1994	1.38506588579795
1995	1.390922401171303
1996	1.3967789165446558
1997	1.4348462664714494
1998	1.437774524158126
1999	1.4494875549048316
2000	1.4348462664714494
2001	1.4348462664714494
2002	1.4348462664714494
2003	1.4348462664714494
2004	1.4348462664714494
2005	1.4348462664714494
2006	1.4348462664714494
2007	1.4348462664714494
2008	1.4348462664714494
2009	1.4641288433382138
2010	1.493411420204978
2011	1.5519765739385067
2012	1.5519765739385067
2013	1.610541727672035
2014	1.610541727672035
2015	1.610541727672035
2016	1.610541727672035
2017	1.610541727672035
2018	1.610541727672035
2019	1.610541727672035
2020	1.610541727672035
2021	1.610541727672035