Year	% of land area
1961	5.573863128511372
1962	5.616500585936897
1963	5.699827811570891
1964	5.7412373779682735
1965	5.788574694156691
1966	5.817027893153665
1967	5.847640486717373
1968	5.919112212769296
1969	5.9607758255862935
1970	5.97847439281953
1971	6.023694655511149
1972	6.058160286439032
1973	6.070439196720464
1974	6.058686309642694
1975	6.110827863281643
1976	6.143897359059905
1977	6.157955070453481
1978	6.224602172060375
1979	6.239972501084074
1980	6.257078872779871
1981	6.256147337687526
1982	6.289809628524553
1983	6.320296231546767
1984	6.345786419073672
1985	6.450795829483518
1986	6.480181527396596
1987	6.481875227564496
1988	6.5317546975091725
1989	6.569016101202989
1990	6.636594737902228
1991	6.732246454884422
1992	6.847545093814264
1993	6.985369944977186
1994	7.0637459202467925
1995	7.26732868042846
1996	7.372549803359293
1997	7.422852698345945
1998	7.452376284623942
1999	7.558201063465867
2000	7.572396667458612
2001	7.629168502037796
2002	7.702879031996155
2003	7.9226301292068815
2004	7.943932967383987
2005	8.087366921100532
2006	8.140754282145311
2007	8.262603480702762
2008	8.389483681061765
2009	8.61314002585285
2010	8.701443407455892
2011	8.85013703758623
2012	9.033505261839164
2013	9.16773106036021
2014	9.241507586579898
2015	9.29981935900277
2016	9.401835759905355
2017	9.48519975483415
2018	9.55066354099153
2019	9.602342744611184
2020	9.630086151948625
2021	9.656653305190146