Year	% of land area
1961	11.32581588265683
1962	11.256757530775165
1963	11.339383266853817
1964	11.302843001913404
1965	11.292184177890423
1966	11.279063996008391
1967	11.237228141289219
1968	11.468212937979489
1969	11.671494456721964
1970	11.558729882590487
1971	11.434899439012359
1972	11.429736278127862
1973	11.344644579483901
1974	11.316075151002524
1975	11.271383726611884
1976	11.293096631106943
1977	11.319017210396304
1978	11.446917316653723
1979	11.477485716494249
1980	11.489938113898903
1981	11.50661138399901
1982	11.484281672866205
1983	11.46847294550111
1984	11.57323359723321
1985	11.560024180231338
1986	11.554870682119194
1987	11.496282776218056
1988	11.43684971032578
1989	11.431760744547725
1990	11.415611809625744
1991	11.409388133408333
1992	11.40868298708153
1993	11.465247840057012
1994	11.438045514780411
1995	11.344863886618546
1996	11.334971914944306
1997	11.338663519822008
1998	11.315570479877264
1999	11.298218574861863
2000	11.298239703277831
2001	11.23710481659836
2002	11.108382949623515
2003	10.985874758839879
2004	10.991695732652413
2005	10.91593502782373
2006	10.74317432877521
2007	10.580629763215102
2008	10.552266519819254
2009	10.570800204857902
2010	10.429260909902526
2011	10.51383303463037
2012	10.490827541489558
2013	10.474053522242896
2014	10.510714079131933
2015	10.48514507489544
2016	10.458183952351446
2017	10.447499233527347
2018	10.429294555523498
2019	10.406890077197373
2020	10.403638688275331
2021	10.481948550044892