Year	% of land area
1961	4.702843083033167
1962	4.754587533252157
1963	4.866723384257238
1964	4.918673714251637
1965	4.972682842000106
1966	5.002260903066929
1967	5.025388064504329
1968	5.066975779136569
1969	5.128602458575102
1970	5.21116024851336
1971	5.263453711466769
1972	5.30394340063017
1973	5.32617841637414
1974	5.346560514139446
1975	5.391648184953606
1976	5.4033833321518125
1977	5.416216504818856
1978	5.494862579024378
1979	5.471941297362385
1980	5.463774732937902
1981	5.474205974891864
1982	5.489166571904781
1983	5.511538840832356
1984	5.520528924358467
1985	5.662036956654965
1986	5.692507163415219
1987	5.693605188884057
1988	5.715497071669015
1989	5.752898564201309
1990	5.744457493409617
1991	5.758731824504511
1992	5.787417739877903
1993	5.922063112994164
1994	5.964886106278846
1995	6.068855392859445
1996	6.100492251680339
1997	6.124237052443961
1998	6.110511734083486
1999	6.15223670189933
2000	6.162736570445094
2001	6.188197036003775
2002	6.250029595217715
2003	6.487065843303118
2004	6.570709613245871
2005	6.720591937636431
2006	6.8012056801087715
2007	6.938144995543804
2008	7.045926011588799
2009	7.294153247366639
2010	7.432403993247028
2011	7.623419371715174
2012	7.839551186815165
2013	7.890774755197485
2014	7.971467110881448
2015	8.016862861999204
2016	8.098773290603274
2017	8.193304738879858
2018	8.256337004238082
2019	8.284319163082722
2020	8.304219726482179
2021	8.322454711806344