Year	% of land area
1961	11.563155922370614
1962	11.629593177676226
1963	11.70903847502532
1964	11.757841916773181
1965	11.842037167422163
1966	11.894317699167328
1967	11.96013404554485
1968	12.00803716934698
1969	12.00968257800642
1970	12.003830511359173
1971	11.981338085439118
1972	12.088227557409782
1973	12.160084959668668
1974	12.151631551965549
1975	12.160959670827937
1976	12.172005828636099
1977	12.181854216231708
1978	12.234514569929306
1979	12.29898779356115
1980	12.248654172258636
1981	12.249548991958337
1982	12.318177369621196
1983	12.237887792483864
1984	12.353621123689535
1985	12.426974650567919
1986	12.436248693482272
1987	12.568233805971403
1988	12.564729455869264
1989	12.625582758830836
1990	12.620637890176791
1991	12.631369776398193
1992	12.443853622711208
1993	12.51217490098922
1994	12.500932884834684
1995	12.537887947358241
1996	12.545694763012802
1997	12.609144508039089
1998	12.646572796383474
1999	12.677773691091847
2000	12.62417289986282
2001	12.675279114979823
2002	12.715824180161894
2003	12.806342372120794
2004	12.859648903624015
2005	12.913865223905074
2006	12.954431360157377
2007	12.984468974532804
2008	12.876814199459544
2009	12.840599223781355
2010	12.923280538734444
2011	12.93821310497134
2012	12.96394231783433
2013	12.951513451868825
2014	12.954748270590205
2015	13.008213356986206
2016	13.031360569665821
2017	13.03796473543871
2018	13.033205821617683
2019	13.011859141070598
2020	13.072582166950427
2021	13.084267531032657