Year	% of land area
1961	9.037652532141427
1962	9.081654264803026
1963	9.154506605714317
1964	9.203407085941855
1965	9.256666663672446
1966	9.291879491440922
1967	9.334744576588072
1968	9.386338017807773
1969	9.399277927130953
1970	9.411033724232064
1971	9.423147246548965
1972	9.505441445266712
1973	9.566237365388382
1974	9.589695842382834
1975	9.612114790968578
1976	9.674714642716063
1977	9.73358951120925
1978	9.820681103180926
1979	9.887829103194292
1980	9.90731804753381
1981	9.940574521360682
1982	10.068289357667043
1983	10.137791697592379
1984	10.305233547814575
1985	10.473671713652905
1986	10.474244718563122
1987	10.518591227446072
1988	10.52054569843908
1989	10.559519013178804
1990	10.581322654767
1991	10.61766341035485
1992	10.548342448879405
1993	10.54285399016346
1994	10.518055980203014
1995	10.543758863461058
1996	10.540476940547546
1997	10.582648512904274
1998	10.586652699410493
1999	10.609125038665047
2000	10.574435677814963
2001	10.602400748208439
2002	10.626446904290317
2003	10.708713215980431
2004	10.72321550578844
2005	10.77547302648431
2006	10.826019646943218
2007	10.866818156179232
2008	10.859162521120691
2009	10.905026854687701
2010	10.949566046440339
2011	10.988036840350889
2012	11.035672465995756
2013	11.0668097797618
2014	11.070582530279902
2015	11.108671658576945
2016	11.140215367799609
2017	11.155239857721224
2018	11.158274787392923
2019	11.139851408205512
2020	11.186482137056698
2021	11.202796325042806