Year	% of land area
1961	8.357041251778094
1962	8.357041251778094
1963	8.357041251778094
1964	8.357041251778094
1965	8.357041251778094
1966	8.357041251778094
1967	8.712660028449502
1968	8.712660028449502
1969	8.712660028449502
1970	8.712660028449502
1971	8.712660028449502
1972	8.712660028449502
1973	8.890469416785205
1974	9.068278805120912
1975	9.068278805120912
1976	9.068278805120912
1977	9.068278805120912
1978	9.068278805120912
1979	9.068278805120912
1980	9.068278805120912
1981	9.139402560455192
1982	9.601706970128022
1983	9.95732574679943
1984	10.135135135135135
1985	10.31294452347084
1986	8.890469416785205
1987	8.534850640113797
1988	8.17923186344239
1989	8.534850640113797
1990	8.890469416785205
1991	8.890469416785205
1992	8.890469416785205
1993	9.601706970128022
1994	9.95732574679943
1995	9.95732574679943
1996	9.601706970128022
1997	9.601706970128022
1998	9.246088193456615
1999	9.95732574679943
2000	10.668563300142248
2001	10.668563300142248
2002	9.95732574679943
2003	9.601706970128022
2004	9.95732574679943
2005	9.95732574679943
2006	9.95732574679943
2007	9.95732574679943
2008	9.95732574679943
2009	9.95732574679943
2010	10.668563300142248
2011	10.668563300142248
2012	10.668563300142248
2013	10.668563300142248
2014	10.668563300142248
2015	10.668563300142248
2016	10.668563300142248
2017	10.668563300142248
2018	10.668563300142248
2019	10.668563300142248
2020	10.668563300142248
2021	10.668563300142248