Year	% of land area
1961	0.17482517482517482
1962	0.17482517482517482
1963	0.17482517482517482
1964	0.17482517482517482
1965	0.17482517482517482
1966	0.17482517482517482
1967	0.18181818181818182
1968	0.18181818181818182
1969	0.18181818181818182
1970	0.1888111888111888
1971	0.1888111888111888
1972	0.1888111888111888
1973	0.1958041958041958
1974	0.1958041958041958
1975	0.1958041958041958
1976	0.2027972027972028
1977	0.2027972027972028
1978	0.2027972027972028
1979	0.2027972027972028
1980	0.2027972027972028
1981	0.2027972027972028
1982	0.2027972027972028
1983	0.2027972027972028
1984	0.2027972027972028
1985	0.2027972027972028
1986	0.2027972027972028
1987	0.2027972027972028
1988	0.2027972027972028
1989	0.2027972027972028
1990	0.2027972027972028
1991	0.2027972027972028
1992	0.26503496503496504
1993	0.32727272727272727
1994	0.3895104895104895
1995	0.45174825174825173
1996	0.513986013986014
1997	0.5762237762237763
1998	0.6384615384615384
1999	0.7006993006993008
2000	0.7610742936867806
2001	0.8231600976630624
2002	0.8371119637251482
2003	0.8719916288803629
2004	0.9068712940355772
2005	0.9277990931287059
2006	0.9417509591907918
2007	0.9417509591907918
2008	0.9766306243460063
2009	1.0254621555633066
2010	1.0603418207185211
2011	1.1761423090338332
2012	1.4509940704569237
2013	1.4788978025810953
2014	1.4788978025810953
2015	1.4788978025810953
2016	1.4788978025810953
2017	1.4788978025810953
2018	1.4788978025810953
2019	1.4788978025810953
2020	1.4788978025810953
2021	1.4788978025810953