Year	% of land area
1961	42.345489458921186
1962	42.328470064154196
1963	42.363195119606196
1964	42.34349928775892
1965	42.324695601605065
1966	42.34926392147032
1967	42.36120494844393
1968	42.39291043385663
1969	42.44197844699533
1970	42.513144222694386
1971	42.62164286433394
1972	42.653005216787626
1973	42.66926971904479
1974	42.6810734928348
1975	42.7127789782475
1976	42.70962215502459
1977	42.73110227825873
1978	42.81029736519867
1979	42.78339574121214
1980	42.776533082031904
1981	42.863002587702894
1982	42.879678849510874
1983	42.90685497986461
1984	42.912550986984215
1985	43.19769447592308
1986	43.45339715697873
1987	43.613365742470066
1988	43.855068598798034
1989	44.051134771577416
1990	44.009271864312055
1991	44.09828055387973
1992	44.27821947758556
1993	43.30941788111143
1994	43.50164096474988
1995	43.6871386423917
1996	43.81162727992121
1997	43.961371189499914
1998	44.10027141130792
1999	44.291190589702126
2000	44.44896312425579
2001	44.54707073912418
2002	44.63605101728285
2003	44.92823463376836
2004	44.63097302753856
2005	44.761451235017326
2006	44.92787439693024
2007	45.08740611872272
2008	45.19073592164181
2009	45.45145615829347
2010	45.62913272488994
2011	45.832552025684606
2012	45.73322401847031
2013	45.848964062364125
2014	45.97760237070639
2015	46.05238750772776
2016	46.15243938018112
2017	46.271150076815175
2018	46.361117623415176
2019	46.41937454680069
2020	46.46760764886201
2021	46.48577931358697