Year	% of land area
1961	5.581668625146886
1962	5.581668625146886
1963	5.581668625146886
1964	5.581668625146886
1965	5.581668625146886
1966	5.581668625146886
1967	5.581668625146886
1968	5.581668625146886
1969	5.581668625146886
1970	5.581668625146886
1971	5.581668625146886
1972	5.581668625146886
1973	5.54249902075989
1974	5.54249902075989
1975	5.54249902075989
1976	5.54249902075989
1977	5.54249902075989
1978	5.54249902075989
1979	5.54249902075989
1980	5.54249902075989
1981	5.54249902075989
1982	5.54249902075989
1983	5.54249902075989
1984	5.54249902075989
1985	5.581668625146886
1986	5.581668625146886
1987	5.581668625146886
1988	5.483744614179397
1989	5.09204857030944
1990	5.09204857030944
1991	5.09204857030944
1992	4.896200548374462
1993	4.504504504504505
1994	4.504504504504505
1995	4.308656482569527
1996	4.112808460634548
1997	4.112808460634548
1998	4.112808460634548
1999	4.308656482569527
2000	4.112808460634548
2001	4.112808460634548
2002	3.916960438699569
2003	4.112808460634548
2004	4.112808460634548
2005	4.112808460634548
2006	4.112808460634548
2007	3.916960438699569
2008	3.916960438699569
2009	4.308656482569527
2010	4.406580493537015
2011	4.5436741088915005
2012	4.5436741088915005
2013	4.5436741088915005
2014	4.5436741088915005
2015	4.964747356051704
2016	4.964747356051704
2017	4.954954954954955
2018	4.945162553858206
2019	4.759106933019976
2020	4.759106933019976
2021	4.759106933019976