Year	% of land area
1961	14.695009242144177
1962	14.279112754158966
1963	14.78743068391867
1964	14.87985212569316
1965	14.417744916820702
1966	14.87985212569316
1967	14.926062846580407
1968	14.87985212569316
1969	14.833641404805913
1970	15.0184842883549
1971	15.064695009242143
1972	15.0184842883549
1973	15.434380776340111
1974	15.665434380776341
1975	15.526802218114602
1976	15.0184842883549
1977	15.0184842883549
1978	15.0184842883549
1979	15.0184842883549
1980	15.0184842883549
1981	15.0184842883549
1982	15.0184842883549
1983	14.556377079482441
1984	15.157116451016636
1985	15.11090573012939
1986	15.619223659889094
1987	15.665434380776341
1988	15.665434380776341
1989	15.619223659889094
1990	15.850277264325324
1991	16.035120147874306
1992	16.035120147874306
1993	16.035120147874306
1994	16.127541589648796
1995	15.942698706099815
1996	15.526802218114602
1997	15.526802218114602
1998	15.480591497227355
1999	15.388170055452866
2000	15.619223659889094
2001	15.804066543438077
2002	16.127541589648796
2003	15.434380776340111
2004	14.371534195933455
2005	14.371534195933455
2006	14.001848428835489
2007	14.131238447319777
2008	13.84935304990758
2009	14.06192236598891
2010	13.56746765249538
2011	13.664510166358596
2012	13.622920517560075
2013	13.207024029574862
2014	13.886321626617375
2015	13.733826247689466
2016	13.632162661737524
2017	17.88354898336414
2018	17.72181146025878
2019	17.46765249537893
2020	17.56007393715342
2021	17.421441774491683