Year	% of land area
1961	12.021857923497267
1962	12.021857923497267
1963	12.021857923497267
1964	12.021857923497267
1965	12.021857923497267
1966	12.021857923497267
1967	12.021857923497267
1968	12.021857923497267
1969	12.021857923497267
1970	12.021857923497267
1971	12.021857923497267
1972	12.021857923497267
1973	12.021857923497267
1974	12.021857923497267
1975	12.021857923497267
1976	12.021857923497267
1977	12.021857923497267
1978	12.021857923497267
1979	12.021857923497267
1980	12.021857923497267
1981	12.021857923497267
1982	12.021857923497267
1983	12.021857923497267
1984	12.021857923497267
1985	12.021857923497267
1986	12.021857923497267
1987	11.748633879781421
1988	11.748633879781421
1989	11.748633879781421
1990	11.748633879781421
1991	11.748633879781421
1992	11.748633879781421
1993	11.748633879781421
1994	11.748633879781421
1995	11.748633879781421
1996	11.748633879781421
1997	11.748633879781421
1998	11.748633879781421
1999	11.748633879781421
2000	12.388360702967445
2001	12.388360702967445
2002	12.964563526361278
2003	12.964563526361278
2004	12.964563526361278
2005	12.964563526361278
2006	12.964563526361278
2007	12.964563526361278
2008	12.964563526361278
2009	12.82051282051282
2010	12.82051282051282
2011	13.108614232209737
2012	13.108614232209737
2013	13.108614232209737
2014	13.108614232209737
2015	13.108614232209737
2016	13.108614232209737
2017	13.396715643906656
2018	13.684817055603574
2019	13.684817055603574
2020	13.972918467300492
2021	13.972918467300492