Year	% of land area
1961	5.663862225690896
1962	5.701906390098505
1963	5.789119905372343
1964	5.829498372295823
1965	5.877624736931557
1966	5.900570434002463
1967	5.925602103534363
1968	5.993346542505613
1969	6.024983791497318
1970	6.042863555448674
1971	6.040380254899874
1972	6.08502999876729
1973	6.072315499957436
1974	6.049340983507875
1975	6.080106313327301
1976	6.110751459717228
1977	6.116860621801444
1978	6.1863461320113435
1979	6.184558084572061
1980	6.196577736802794
1981	6.189226875107966
1982	6.2093225416061255
1983	6.233192974920549
1984	6.236451194698797
1985	6.3113306480172
1986	6.3381811603970934
1987	6.3486909059013215
1988	6.408918303814492
1989	6.428070278608585
1990	6.506327154867855
1991	6.556471951942847
1992	6.560211951170014
1993	6.702525626941584
1994	6.708025842794157
1995	6.83766909257327
1996	6.9558350914808935
1997	6.990828285371757
1998	7.00336382820672
1999	7.049088996938456
2000	7.073341487836238
2001	7.107033340734624
2002	7.175009282251545
2003	7.429849008211359
2004	7.461625316552682
2005	7.627459391882341
2006	7.719418656702493
2007	7.869067641935041
2008	7.985560643261244
2009	8.202647669513292
2010	8.369121115845712
2011	8.524941229987572
2012	8.748663252235303
2013	8.880803254438385
2014	8.957683132855472
2015	9.038480403568503
2016	9.15427721404688
2017	9.252746108105155
2018	9.318728869046119
2019	9.348213752846169
2020	9.379956891985692
2021	9.418217900688486