Year	% of land area
1961	7.851106505362971
1962	7.869090610203663
1963	7.893971428067948
1964	7.92036353899747
1965	7.931427512434183
1966	7.943160524772606
1967	7.944959298645336
1968	7.958688122263872
1969	7.958867394003376
1970	7.970373490311165
1971	8.002919790099982
1972	8.057446258706687
1973	8.121268808887475
1974	8.21842213565203
1975	8.223009673711674
1976	8.357252170892075
1977	8.501319850269157
1978	8.622124289018148
1979	8.71781934695193
1980	8.822869117757689
1981	8.897607716970429
1982	9.142339572276466
1983	9.413487653725594
1984	9.729240709739763
1985	10.034284220256298
1986	10.001135620512214
1987	9.945972503705072
1988	9.910492052375197
1989	9.884519650168757
1990	9.88908061228759
1991	9.873461227585452
1992	9.408731976811687
1993	9.309610078977087
1994	9.234008667154407
1995	9.141980865069756
1996	9.083598863360772
1997	9.117998805327336
1998	9.103322776510812
1999	9.079568177541665
2000	9.048004031922845
2001	9.025947288405375
2002	8.993242597252015
2003	8.990660382692894
2004	8.961766926979143
2005	8.959915118155262
2006	9.015551625769442
2007	9.008389650150772
2008	9.04394594961399
2009	9.062566348083875
2010	9.026259071568195
2011	9.028915517535244
2012	9.004828878924817
2013	8.9921140345068
2014	8.971895239138373
2015	8.98183833046029
2016	8.974978225897644
2017	8.965388747242107
2018	8.946824962041397
2019	8.902707279586675
2020	8.932189911211326
2021	8.948635942166199