Year	% of land area
1961	57.14285714285714
1962	57.14285714285714
1963	57.14285714285714
1964	57.14285714285714
1965	57.14285714285714
1966	57.14285714285714
1967	57.14285714285714
1968	57.14285714285714
1969	51.42857142857142
1970	42.857142857142854
1971	42.857142857142854
1972	42.857142857142854
1973	42.857142857142854
1974	42.857142857142854
1975	42.857142857142854
1976	42.857142857142854
1977	42.857142857142854
1978	42.857142857142854
1979	42.857142857142854
1980	57.692307692307686
1981	57.692307692307686
1982	53.84615384615385
1983	53.84615384615385
1984	50
1985	50
1986	46.15384615384615
1987	46.15384615384615
1988	46.15384615384615
1989	46.15384615384615
1990	46.15384615384615
1991	46.15384615384615
1992	46.15384615384615
1993	46.15384615384615
1994	38.46153846153847
1995	38.46153846153847
1996	34.61538461538461
1997	34.61538461538461
1998	34.61538461538461
1999	38.46153846153847
2000	36.53846153846153
2001	35.76923076923077
2002	31.153846153846153
2003	31.153846153846153
2004	30.884615384615383
2005	19.230769230769234
2006	19.26923076923077
2007	19.576923076923077
2008	19.615384615384617
2009	21.153846153846153
2010	21.923076923076923
2011	23.076923076923077
2012	23.076923076923077
2013	23.076923076923077
2014	23.076923076923077
2015	23.076923076923077
2016	23.076923076923077
2017	23.076923076923077
2018	23.076923076923077
2019	23.076923076923077
2020	23.076923076923077
2021	23.076923076923077