Year	% of land area
1961	7.7263874323138495
1962	7.769192902852986
1963	7.769192902852986
1964	7.811998373392119
1965	7.833401108661688
1966	7.876206579200821
1967	7.876206579200821
1968	7.9190120497399565
1969	7.9190120497399565
1970	8.175844872974766
1971	8.175844872974766
1972	8.240053078783468
1973	8.240053078783468
1974	8.389872225670441
1975	8.389872225670441
1976	8.518288637287846
1977	8.56109410782698
1978	8.56109410782698
1979	8.668107784174818
1980	8.839329666331357
1981	8.839329666331357
1982	8.946343342679194
1983	9.203176165914003
1984	9.502814459687949
1985	9.502814459687949
1986	9.502814459687949
1987	9.952271900348865
1988	9.845258224001027
1989	9.674036341844488
1990	9.716841812383622
1991	10.786978575861996
1992	10.786978575861996
1993	10.808381311131562
1994	12.78894472361809
1995	14.195979899497488
1996	14.321608040201006
1997	14.37185929648241
1998	14.37185929648241
1999	14.37185929648241
2000	14.522613065326635
2001	14.547738693467338
2002	14.572864321608039
2003	14.648241206030152
2004	15.321247737230106
2005	15.557362856468243
2006	15.137602644489334
2007	14.770312459007792
2008	13.676312406537766
2009	13.64220688931448
2010	13.64220688931448
2011	13.631712884015007
2012	13.631712884015007
2013	13.631712884015007
2014	13.789122963507097
2015	13.789122963507097
2016	13.60633389261745
2017	13.449035234899329
2018	13.450445726271631
2019	13.450445726271631
2020	13.450445726271631
2021	13.450445726271631