Year	% of land area
1961	15.327793167128348
1962	15.327793167128348
1963	15.327793167128348
1964	15.327793167128348
1965	13.850415512465375
1966	13.850415512465375
1967	14.312096029547552
1968	14.312096029547552
1969	14.312096029547552
1970	13.388734995383194
1971	13.388734995383194
1972	13.388734995383194
1973	13.388734995383194
1974	13.388734995383194
1975	13.388734995383194
1976	13.388734995383194
1977	13.388734995383194
1978	13.388734995383194
1979	12.465373961218837
1980	12.465373961218837
1981	12.465373961218837
1982	11.542012927054477
1983	10.61865189289012
1984	10.61865189289012
1985	10.61865189289012
1986	10.61865189289012
1987	10.61865189289012
1988	10.61865189289012
1989	11.080332409972298
1990	10.987996306555864
1991	11.634349030470915
1992	12.557710064635272
1993	16.06648199445983
1994	14.866112650046167
1995	14.58910433979686
1996	14.312096029547552
1997	13.850415512465375
1998	13.388734995383194
1999	13.204062788550322
2000	12.927054478301015
2001	12.927054478301015
2002	12.465373961218837
2003	12.465373961218837
2004	12.280701754385964
2005	11.819021237303785
2006	11.819021237303785
2007	11.542012927054477
2008	11.080332409972298
2009	11.080332409972298
2010	11.080332409972298
2011	11.080332409972298
2012	11.080332409972298
2013	11.080332409972298
2014	11.080332409972298
2015	11.080332409972298
2016	11.080332409972298
2017	11.080332409972298
2018	11.080332409972298
2019	11.080332409972298
2020	11.080332409972298
2021	11.080332409972298