Year	% of land area
1961	4.404025913901069
1962	4.459728803655385
1963	4.522456834246336
1964	4.585384159612794
1965	4.630923015816233
1966	4.704114022121321
1967	4.76988129803876
1968	4.879593071955578
1969	4.909287993506179
1970	4.901565320955267
1971	4.966236475607416
1972	5.072410767258978
1973	5.156474434565845
1974	5.224958237779792
1975	5.310763566697916
1976	5.478060476168791
1977	5.635906308981882
1978	5.784933362337352
1979	5.919446775915358
1980	6.072238221781292
1981	6.128872113627174
1982	6.192735855843934
1983	6.275333371664515
1984	6.335365651567968
1985	6.429338320771401
1986	6.398441643168058
1987	6.387540145601357
1988	6.361281927897653
1989	6.343095180774036
1990	6.324604507906354
1991	6.303772112092598
1992	6.253693086416751
1993	6.210793693610564
1994	6.179094706849171
1995	6.172675227142143
1996	6.207230921584567
1997	6.275244854537153
1998	6.347762078357419
1999	6.3965684027292
2000	6.436649143318113
2001	6.480231987367462
2002	6.5147080499463055
2003	6.672214569657763
2004	6.7698732791842735
2005	6.8973719805529115
2006	7.014165090167565
2007	7.132775936353677
2008	7.102029503945163
2009	7.082615696863649
2010	7.281897308611258
2011	7.3455557482096685
2012	7.413566006989211
2013	7.432801145284862
2014	7.433394029486673
2015	7.522411213266814
2016	7.4942944757905625
2017	7.459164912034858
2018	7.49253258185812
2019	7.513615558054071
2020	7.653476144660111
2021	7.715978691737309