Year	% of land area
1961	11.13338352268197
1962	11.05691972887202
1963	11.135219701878196
1964	11.10600275795722
1965	11.099180569905181
1966	11.079518961025407
1967	11.046941751091456
1968	11.318263321453818
1969	11.524518915233687
1970	11.451802023155668
1971	11.301995236044448
1972	11.29057238084957
1973	11.19530808553712
1974	11.169344591008599
1975	11.127374255377179
1976	11.156313802649972
1977	11.180950801554793
1978	11.330966356637273
1979	11.35296813230812
1980	11.377697578522245
1981	11.402564126005743
1982	11.4199353288411
1983	11.404534003230653
1984	11.500760421564028
1985	11.484334611355878
1986	11.485127631520736
1987	11.386667699491534
1988	11.318249482819274
1989	11.286194170045443
1990	11.25596312595187
1991	11.239809408888632
1992	12.219490596590688
1993	12.256216849660571
1994	12.228366083101763
1995	12.171705315411579
1996	12.162553776916662
1997	12.169097463262007
1998	12.107433644467442
1999	12.094000557115793
2000	12.088361819180644
2001	12.038581317791571
2002	11.911260183967363
2003	11.791098304380341
2004	11.794098680325106
2005	11.720472581177916
2006	11.545860685445453
2007	11.400071394836981
2008	11.385932431213215
2009	11.42034238932894
2010	11.30469775168689
2011	11.431448533058424
2012	11.412033183346905
2013	11.418813615295482
2014	11.458411814506697
2015	11.434508983037722
2016	11.417826842827399
2017	11.452853759901027
2018	11.440790414613277
2019	11.434560406968655
2020	11.408614117641518
2021	11.49476546004776