Year	% of land area
1961	14.754098360655737
1962	14.754098360655737
1963	16.39344262295082
1964	16.39344262295082
1965	16.39344262295082
1966	16.39344262295082
1967	18.0327868852459
1968	18.0327868852459
1969	18.0327868852459
1970	18.0327868852459
1971	19.672131147540984
1972	19.672131147540984
1973	19.672131147540984
1974	19.01639344262295
1975	19.672131147540984
1976	19.672131147540984
1977	19.672131147540984
1978	19.672131147540984
1979	20.491803278688526
1980	21.311475409836063
1981	22.131147540983605
1982	22.950819672131146
1983	23.770491803278688
1984	24.59016393442623
1985	25.40983606557377
1986	26.065573770491802
1987	26.229508196721312
1988	26.229508196721312
1989	26.229508196721312
1990	26.229508196721312
1991	24.59016393442623
1992	24.59016393442623
1993	24.59016393442623
1994	24.59016393442623
1995	22.950819672131146
1996	22.62295081967213
1997	22.131147540983605
1998	19.672131147540984
1999	19.672131147540984
2000	17.868852459016395
2001	17.37704918032787
2002	16.229508196721312
2003	15.081967213114755
2004	13.114754098360656
2005	12.622950819672132
2006	11.475409836065573
2007	11.311475409836065
2008	11.311475409836065
2009	11.311475409836065
2010	11.311475409836065
2011	11.311475409836065
2012	11.311475409836065
2013	11.311475409836065
2014	11.311475409836065
2015	11.311475409836065
2016	11.311475409836065
2017	11.311475409836065
2018	11.311475409836065
2019	11.311475409836065
2020	11.311475409836065
2021	11.311475409836065