Year	% of land area
1961	2.6967157854184727
1962	2.712767665093583
1963	2.7288195447686925
1964	2.7448714244438026
1965	2.7609233041189123
1966	2.7769751837940224
1967	2.7930270634691325
1968	2.8090789431442422
1969	2.8251308228193523
1970	2.841182702494462
1971	2.857234582169572
1972	2.8732864618446823
1973	2.889338341519792
1974	2.905390221194902
1975	2.9214421008700118
1976	2.937493980545122
1977	2.9535458602202316
1978	2.9695977398953417
1979	2.985649619570452
1980	3.0017014992455615
1981	3.0017014992455615
1982	3.0017014992455615
1983	3.0017014992455615
1984	3.0017014992455615
1985	3.0017014992455615
1986	3.0017014992455615
1987	3.0017014992455615
1988	3.0017014992455615
1989	3.0017014992455615
1990	3.0017014992455615
1991	3.0017014992455615
1992	3.0017014992455615
1993	3.0017014992455615
1994	3.0017014992455615
1995	3.0017014992455615
1996	3.0017014992455615
1997	3.0017014992455615
1998	3.0017014992455615
1999	3.0017014992455615
2000	3.0017014992455615
2001	3.0017014992455615
2002	3.0017014992455615
2003	3.0017014992455615
2004	3.0017014992455615
2005	3.0017014992455615
2006	3.0017014992455615
2007	3.0017014992455615
2008	3.0017014992455615
2009	2.9952807473755176
2010	2.9439147324151658
2011	2.889338341519792
2012	2.889338341519792
2013	2.889338341519792
2014	2.889338341519792
2015	2.889338341519792
2016	2.889338341519792
2017	2.889338341519792
2018	2.889338341519792
2019	2.889338341519792
2020	2.889338341519792
2021	2.889338341519792