Year	% of land area
1961	5.573796909339924
1962	5.616433536336462
1963	5.699759139046678
1964	5.741167898930109
1965	5.7885042931526804
1966	5.816956937980559
1967	5.847568935317696
1968	5.919039269349629
1969	5.960702070704738
1970	5.978400293231602
1971	6.023619675190195
1972	6.058084634847774
1973	6.070363305978853
1974	6.058610646524902
1975	6.110751183312331
1976	6.143820034990317
1977	6.157877472579423
1978	6.224523276089218
1979	6.239893305742366
1980	6.256999344254409
1981	6.256067827305734
1982	6.289729462496513
1983	6.320215471725899
1984	6.3457051627760235
1985	6.450712527899462
1986	6.480097653462231
1987	6.481791320641641
1988	6.531669819075274
1989	6.568930497022301
1990	6.636507817480771
1991	6.732157671437967
1992	6.847454064676323
1993	6.985276231400835
1994	7.063650680128046
1995	7.267229475093163
1996	7.372448548614027
1997	7.4227504638425135
1998	7.452273475084525
1999	7.558096192758971
2000	7.572291520261489
2001	7.6290622490858535
2002	7.702771343371501
2003	7.922518160452185
2004	7.94382128630966
2005	8.087252464021432
2006	8.140638791696066
2007	8.262485632046744
2008	8.389363376405477
2009	8.61301539241561
2010	8.701312860971525
2011	8.849971427068203
2012	9.033337189077596
2013	9.167560821490712
2014	9.241335926865005
2015	9.299646576926667
2016	9.40166101364198
2017	9.48502340337597
2018	9.550485929192215
2019	9.602164137862049
2020	9.629907010675534
2021	9.656473652387168