Year	% of land area
1961	2.798747450073412
1962	2.8806049660226343
1963	2.890999571222536
1964	2.9468705741720047
1965	2.9949456232215477
1966	3.097592349570573
1967	3.1365721190702023
1968	3.2600080558190294
1969	3.263906032768993
1970	3.358756805218092
1971	3.4250224133674623
1972	3.4471109494172523
1973	3.565349583566129
1974	3.5952340735158455
1975	3.578342840066006
1976	3.691384171614932
1977	3.7238673128646234
1978	3.7966295492639324
1979	3.9161675090627965
1980	4.060392656211427
1981	3.936956719462599
1982	3.7576497797643023
1983	3.7966295492639324
1984	3.782336967114068
1985	3.8135207827137716
1986	3.800527526213895
1987	3.8499019009134257
1988	3.868092460013253
1989	3.9200654860127595
1990	3.936956719462599
1991	3.9278614399126854
1992	3.913568857762821
1993	3.9681405350623025
1994	3.9837324428621548
1995	3.1976404246196224
1996	3.2119330067694865
1997	3.335368943518314
1998	3.2872938944687706
1999	3.278198614918857
2000	3.317178384418487
2001	3.313280407468524
2002	3.358756805218092
2003	3.4497096007172274
2004	3.5367644192664005
2005	3.6069280043657344
2006	3.7615477567142652
2007	3.7797383158140927
2008	3.8330106674635864
2009	3.8239153879136727
2010	3.912269532112833
2011	4.016215584111846
2012	4.17473331341034
2013	4.199420500760106
2014	4.207216454660031
2015	4.266985434559464
2016	4.3254550888089085
2017	4.350142276158674
2018	4.491768772007329
2019	4.572326962306563
2020	4.62429998830607
2021	4.665878409105674