Year	% of land area
1961	23.613678373382623
1962	23.33641404805915
1963	24.12199630314233
1964	24.260628465804064
1965	23.752310536044362
1966	24.260628465804064
1967	24.260628465804064
1968	24.075785582255083
1969	24.168207024029577
1970	24.260628465804064
1971	24.35304990757856
1972	24.35304990757856
1973	24.81515711645102
1974	25.184842883548985
1975	24.953789279112755
1976	24.491682070240294
1977	24.53789279112754
1978	24.630314232902034
1979	24.630314232902034
1980	24.630314232902034
1981	24.861367837338264
1982	24.953789279112755
1983	25.55452865064695
1984	26.062846580406656
1985	26.571164510166355
1986	26.756007393715343
1987	26.66358595194085
1988	26.617375231053604
1989	26.571164510166355
1990	26.756007393715343
1991	26.709796672828094
1992	26.66358595194085
1993	26.66358595194085
1994	26.756007393715343
1995	26.478743068391868
1996	26.062846580406656
1997	26.01663585951941
1998	25.970425138632162
1999	25.831792975970423
2000	26.155268022181144
2001	25.924214417744917
2002	26.01663585951941
2003	25.46210720887246
2004	23.72920517560074
2005	23.775415896487985
2006	23.512014787430687
2007	23.941774491682068
2008	23.826247689463955
2009	24.149722735674676
2010	23.313308687615528
2011	23.890942698706098
2012	24.316081330868762
2013	24.04343807763401
2014	24.84750462107209
2015	24.671903881700555
2016	25.508317929759706
2017	29.75970425138632
2018	29.634935304990755
2019	29.500924214417743
2020	29.87060998151571
2021	29.7365988909427