Year	% of land area
1961	7.881672762974359
1962	7.929191036931053
1963	8.026514115962215
1964	8.093405544480431
1965	8.176344264116128
1966	8.194428646593085
1967	8.227812000912618
1968	8.268553828102082
1969	8.244981770942463
1970	8.277013993237855
1971	8.269967320065799
1972	8.320645164294328
1973	8.348374550758995
1974	8.319424063953427
1975	8.362240037144263
1976	8.392417534200376
1977	8.413448651666279
1978	8.507318181281494
1979	8.518546051418262
1980	8.58216186141046
1981	8.550634583842413
1982	8.66663418456155
1983	8.601144747876836
1984	8.675840148630265
1985	8.771181413201479
1986	8.737084831468055
1987	8.805677521086137
1988	8.821544682289009
1989	8.884856583170237
1990	8.929040091224286
1991	9.019810353517759
1992	9.078441619546977
1993	9.219637726124935
1994	9.283452482408235
1995	9.491107765283694
1996	9.583839712702133
1997	9.66061075711646
1998	9.697241940641003
1999	9.7959267324
2000	9.784063505882425
2001	9.86288494215365
2002	9.914525955077089
2003	10.118182391149094
2004	10.10742242949333
2005	10.244820998554767
2006	10.331438888163547
2007	10.442206049284405
2008	10.522670087947152
2009	10.711931789746336
2010	10.80441364800123
2011	10.96281080521846
2012	11.136158935486778
2013	11.270749940993179
2014	11.330902403903185
2015	11.393416727983693
2016	11.50701423232736
2017	11.598262279101228
2018	11.663418479249346
2019	11.682513769424851
2020	11.725582273632307
2021	11.739377988828304