Year	% of land area
1961	44.277330709491515
1962	44.2861158941561
1963	44.29490107882067
1964	44.30368626348526
1965	44.31247144814984
1966	44.32125663281442
1967	44.33004181747901
1968	44.33882700214358
1969	44.34761218680816
1970	44.35639737147275
1971	44.36518255613733
1972	44.37396774080191
1973	44.3827529254665
1974	44.39153811013107
1975	44.93094844853639
1976	44.94149067013389
1977	44.94500474399972
1978	44.94500474399972
1979	44.94500474399972
1980	44.94500474399972
1981	44.94500474399972
1982	44.94500474399972
1983	44.94500474399972
1984	44.813226974031
1985	46.30495133007696
1986	46.338335031802366
1987	46.44727132164318
1988	46.846118705415186
1989	47.53312014618547
1990	47.03587869417015
1991	47.2238816459922
1992	47.56650384791089
1993	47.1588712794743
1994	47.847629757177494
1995	47.82303124011666
1996	46.47538391256984
1997	46.72664019397688
1998	46.48768317110026
1999	47.222124609059286
2000	46.861932037811435
2001	47.157114242541375
2002	47.12021646695014
2003	47.21861053519345
2004	47.42594089327758
2005	47.44351126260674
2006	47.53487718311839
2007	47.56298977404505
2008	47.589345328038796
2009	47.94075271462206
2010	47.984678637944974
2011	48.531117124081945
2012	48.55044453034403
2013	48.56977193660611
2014	48.58909934286819
2015	48.61018378606318
2016	48.62951119232527
2017	48.64883859858734
2018	48.668166004849425
2019	48.687493411111504
2020	48.687493411111504
2021	48.687493411111504