Year	% of land area
1961	38.01587301587301
1962	38.01587301587301
1963	38.01587301587301
1964	38.01587301587301
1965	38.01587301587301
1966	38.01587301587301
1967	38.01587301587301
1968	38.01587301587301
1969	38.01587301587301
1970	38.01587301587301
1971	38.01587301587301
1972	38.01587301587301
1973	38.023809523809526
1974	38.04382343601143
1975	38.11944091486658
1976	38.19885641677255
1977	38.19885641677255
1978	38.23856416772554
1979	38.23856416772554
1980	38.23856416772554
1981	38.23856416772554
1982	38.23856416772554
1983	38.23856416772554
1984	38.23856416772554
1985	38.24253494282084
1986	38.282242693773824
1987	38.282242693773824
1988	38.30209656925032
1989	38.31797966963151
1990	38.3576874205845
1991	38.39739517153748
1992	38.41327827191868
1993	38.43710292249047
1994	38.45298602287166
1995	38.47681067344346
1996	38.46092757306226
1997	38.619758576874204
1998	38.619758576874204
1999	38.619758576874204
2000	38.619758576874204
2001	38.69917407878018
2002	38.69917407878018
2003	38.77858958068615
2004	38.77858958068615
2005	38.85800508259212
2006	38.85800508259212
2007	38.85879923761118
2008	38.85879923761118
2009	38.94139135959339
2010	39.10022236340534
2011	39.17963786531131
2012	39.45759212198221
2013	39.73634053367217
2014	39.89517153748412
2015	39.895965692503175
2016	39.9761753494282
2017	39.9761753494282
2018	39.9761753494282
2019	39.9761753494282
2020	39.9761753494282
2021	39.9761753494282