Year	% of land area
1961	0.5369166503903707
1962	0.5563931632189781
1963	0.5608812292186137
1964	0.578240729783242
1965	0.5889528118389762
1966	0.5905617411596003
1967	0.5824747543112002
1968	0.5892491935559332
1969	0.6001306365927856
1970	0.6070320965733573
1971	0.6158388675915103
1972	0.62193586291177
1973	0.6348919779673219
1974	0.6487482254373409
1975	0.6639598760083195
1976	0.6687868274696388
1977	0.687247799725211
1978	0.6972827777632169
1979	0.7069790223653408
1980	0.7167599503264352
1981	0.7264985366080444
1982	0.7359830728127421
1983	0.7433928667226621
1984	0.7590592881322074
1985	0.7834057538362302
1986	0.7942028821049709
1987	0.8005117923482742
1988	0.8147809383348059
1989	0.8215556070524471
1990	0.8301509679879543
1991	0.84590207275647
1992	0.8564028092688138
1993	0.8751601732807828
1994	0.8904455195749607
1995	0.903020998382082
1996	0.9096686420612675
1997	0.9189838115480241
1998	0.9361240917762678
1999	0.9498346959662056
2000	0.9748928702581924
2001	0.9899160665121731
2002	0.9971907354203519
2003	1.0144580406870514
2004	1.0287255244164268
2005	1.0468716971194416
2006	1.057951256828504
2007	1.0799893950340704
2008	1.094003080968104
2009	1.1131931935280084
2010	1.1469396466548318
2011	1.1572165054888603
2012	1.1637975317038167
2013	1.190753120126492
2014	1.2233247979269757
2015	1.2729940755255689
2016	1.2667447790164668
2017	1.2876575185359063
2018	1.351982824532141
2019	1.3739029663937528
2020	1.396504591262717
2021	1.4085175519862698