Year	% of land area
1961	25.99558615237656
1962	26.15698804308442
1963	26.319487905837917
1964	26.48088979654578
1965	26.642291687253643
1966	26.804791550007135
1967	26.966193440714996
1968	27.12869330346849
1969	27.290095194176356
1970	27.45149708488422
1971	27.613996947637716
1972	27.775398838345577
1973	27.93680072905344
1974	28.09930059180693
1975	28.260702482514795
1976	28.422104373222655
1977	28.58460423597615
1978	28.746006126684016
1979	28.907408017391877
1980	29.069907880145372
1981	29.231309770853237
1982	29.393809633606725
1983	29.55521152431459
1984	29.71661341502245
1985	29.87911327777595
1986	30.04051516848381
1987	30.17446775805088
1988	30.427001328546176
1989	30.620244408577356
1990	30.82446720906486
1991	31.84118932331983
1992	33.04895857351472
1993	33.04895857351472
1994	34.037133414583266
1995	36.12328030128353
1996	36.34287471040987
1997	36.452671914973045
1998	37.331049551478415
1999	38.429021597110136
2000	38.429021597110136
2001	39.143801398816386
2002	39.18442636450476
2003	39.218463497919345
2004	39.25359860337956
2005	39.287635736794144
2006	39.32277084225436
2007	39.35680797566894
2008	39.391943081129156
2009	40.48442526653272
2010	39.461115320003955
2011	39.495152453418534
2012	39.530287558878754
2013	39.56432469229333
2014	39.59945979775355
2015	39.63349693116813
2016	39.668632036628345
2017	39.70266917004293
2018	39.98814190190718
2019	40.48442526653272
2020	40.48442526653272
2021	40.48442526653272