Year	% of land area
1961	1.5046895068306703
1962	1.51121744395358
1963	1.51121744395358
1964	1.5185613732168532
1965	1.5185613732168532
1966	1.5283532789012175
1967	1.5426331413575824
1968	1.5450811177786736
1969	1.5479370902699465
1970	1.5583409900595837
1971	1.563032944866675
1972	1.576904811252858
1973	1.5915926697794047
1974	1.5672353043895482
1975	1.543524166674826
1976	1.5502421318372157
1977	1.5322369065220158
1978	1.5611485902093063
1979	1.5640316113618784
1980	1.5593427562183453
1981	1.555208493978509
1982	1.566700162460721
1983	1.5655441699774872
1984	1.5863787578731436
1985	1.585345202512878
1986	1.5688896695054455
1987	1.5964193363344912
1988	1.6139859423741787
1989	1.6091947790623953
1990	1.6317796343940199
1991	1.603387016931211
1992	1.9979097756777686
1993	2.0580574666386617
1994	2.057134846883754
1995	2.034286728344322
1996	2.035796728219718
1997	2.020545476250673
1998	1.9880103992112164
1999	1.9893194248438733
2000	2.0383517941573572
2001	1.917994992525768
2002	1.890532545567895
2003	1.8502766801278674
2004	1.8602404535724542
2005	1.892746763370053
2006	1.9183350815585047
2007	1.9197195810037093
2008	1.9713261361972527
2009	2.006690408201311
2010	2.015537864543745
2011	2.033356776409065
2012	2.0031564103333435
2013	1.9307729065822121
2014	2.001442832943299
2015	1.9453376591540656
2016	1.9975138672780226
2017	2.0127008978751966
2018	2.022370940572915
2019	2.0218776169996295
2020	2.0266257759000963
2021	2.0272249256945045