Year	% of land area
1961	1.403125
1962	1.50703125
1963	1.7187500000000002
1964	1.88984375
1965	1.9617187500000002
1966	1.88828125
1967	1.8953125000000002
1968	1.9140625000000002
1969	1.92265625
1970	1.9984374999999999
1971	1.9984374999999999
1972	2.4554687499999996
1973	2.497048984375
1974	2.5386292968750004
1975	2.5802095312500004
1976	2.621789765625
1977	2.66337
1978	2.7049503125
1979	2.746530546875
1980	2.78811078125
1981	2.829691015625
1982	2.871271328125
1983	2.9128515625
1984	2.9544317968750002
1985	2.996012109375
1986	3.03759234375
1987	3.0791725781249997
1988	3.1207528125
1989	3.162333125
1990	3.203913359375
1991	3.24549359375
1992	3.287073828125
1993	3.3286541406250003
1994	3.3702343750000003
1995	3.3967187500000002
1996	3.423203125
1997	3.4496875000000005
1998	3.4761718749999995
1999	3.50265625
2000	3.5291406249999997
2001	3.5556249999999996
2002	3.582109375
2003	3.60859375
2004	3.6350781249999997
2005	3.6615625
2006	3.688046875
2007	3.71453125
2008	3.741015625
2009	3.7675
2010	3.793984375
2011	3.82046875
2012	3.8469999999999995
2013	3.64993203125
2014	3.4528640625
2015	3.25580703125
2016	2.967321875
2017	2.93501953125
2018	2.97996171875
2019	2.7970515625
2020	3.0744230468750002
2021	3.3517937499999997