Year	% of land area
1961	5.738389231436771
1962	5.764651540274446
1963	5.85365435542452
1964	5.901195612789117
1965	5.936029301361289
1966	5.962291610198966
1967	5.993088776919427
1968	6.067938848786958
1969	6.100280857203754
1970	6.118370455131792
1971	6.156094492684203
1972	6.187140827420203
1973	6.201443071512068
1974	6.1869153187114305
1975	6.239964046612025
1976	6.277589916984373
1977	6.294733359908992
1978	6.368041512647699
1979	6.384586928493554
1980	6.407361793076551
1981	6.415086309510609
1982	6.451765303674911
1983	6.494773417756152
1984	6.5294091527346705
1985	6.6533004292189855
1986	6.686540767680384
1987	6.695710516221459
1988	6.755563059687937
1989	6.788255206660467
1990	6.861712866168865
1991	6.993428330267032
1992	7.111040322424306
1993	7.259688497747878
1994	7.320084250587631
1995	7.529287601351933
1996	7.618591994508251
1997	7.632971935660573
1998	7.676458861145354
1999	7.774986251040748
2000	7.7736970149374365
2001	7.846891907122836
2002	7.93620423403979
2003	8.149879746502464
2004	8.159138395435633
2005	8.310950979587066
2006	8.370134506986846
2007	8.492208077228756
2008	8.584603930462986
2009	8.824894212032433
2010	8.926638767022725
2011	9.094177186658099
2012	9.312914381337011
2013	9.474825865954434
2014	9.563833964091243
2015	9.63317014081154
2016	9.73631508909925
2017	9.82133738241515
2018	9.891813590639856
2019	9.951742134319195
2020	9.982753271362334
2021	10.00555140516022