Year	% of land area
1961	41.17647058823529
1962	41.17647058823529
1963	41.17647058823529
1964	41.17647058823529
1965	41.17647058823529
1966	41.17647058823529
1967	41.17647058823529
1968	41.17647058823529
1969	41.17647058823529
1970	41.17647058823529
1971	41.17647058823529
1972	41.17647058823529
1973	41.17647058823529
1974	41.17647058823529
1975	41.17647058823529
1976	41.17647058823529
1977	41.17647058823529
1978	41.17647058823529
1979	41.17647058823529
1980	35.294117647058826
1981	35.294117647058826
1982	35.294117647058826
1983	35.294117647058826
1984	35.294117647058826
1985	29.411764705882355
1986	29.411764705882355
1987	29.411764705882355
1988	29.411764705882355
1989	29.411764705882355
1990	29.411764705882355
1991	26.47058823529412
1992	26.47058823529412
1993	26.47058823529412
1994	26.47058823529412
1995	26.47058823529412
1996	26.47058823529412
1997	26.47058823529412
1998	26.47058823529412
1999	29.411764705882355
2000	29.411764705882355
2001	29.411764705882355
2002	29.411764705882355
2003	26.47058823529412
2004	26.47058823529412
2005	17.647058823529413
2006	17.647058823529413
2007	17.647058823529413
2008	17.647058823529413
2009	17.647058823529413
2010	17.647058823529413
2011	17.647058823529413
2012	11.76470588235294
2013	11.76470588235294
2014	11.76470588235294
2015	11.76470588235294
2016	11.76470588235294
2017	11.76470588235294
2018	11.76470588235294
2019	11.76470588235294
2020	11.76470588235294
2021	11.76470588235294