Year	% of land area
1961	9.178279714460366
1962	9.218983837551287
1963	9.285632644023174
1964	9.329448172870933
1965	9.378708998612868
1966	9.41306177978862
1967	9.450065466813147
1968	9.49545017132774
1969	9.504795436284756
1970	9.510111394410137
1971	9.521014517891718
1972	9.593811361901572
1973	9.649221682203153
1974	9.674272462690558
1975	9.692976954089275
1976	9.751640395179608
1977	9.807344904629934
1978	9.889431348340004
1979	9.952618153847752
1980	9.968972765694513
1981	9.995892725220969
1982	10.116612296849796
1983	10.181256144793544
1984	10.343608006160528
1985	10.508406250666239
1986	10.508703091221724
1987	10.547772006618263
1988	10.548786243847811
1989	10.573606789282547
1990	10.590519358760908
1991	10.623063432186614
1992	10.55345278429287
1993	10.544172501980677
1994	10.518840610157735
1995	10.541515435808568
1996	10.536694135325828
1997	10.576581133381515
1998	10.58269247615501
1999	10.602869982192054
2000	10.567155607405946
2001	10.587732290444206
2002	10.603511173907012
2003	10.678337097378927
2004	10.688751071213412
2005	10.735150677851289
2006	10.785734065099343
2007	10.817386780559568
2008	10.817045110812648
2009	10.866338046691839
2010	10.90048577452415
2011	10.943662905446693
2012	10.986335213977794
2013	11.015376067134653
2014	11.022408331726242
2015	11.060340040330672
2016	11.086790723396248
2017	11.102050356070253
2018	11.107168493485926
2019	11.092223596246047
2020	11.133732816230753
2021	11.149803473130095