Year	% of land area
1961	4.9182599057910785
1962	4.987531172069826
1963	5.056802438348573
1964	5.126073704627321
1965	5.195344970906069
1966	5.264616237184816
1967	5.333887503463563
1968	5.403158769742311
1969	5.472430036021059
1970	5.541701302299806
1971	5.610972568578553
1972	5.680243834857301
1973	5.7495151011360495
1974	5.818786367414797
1975	5.888057633693544
1976	5.957328899972292
1977	6.02660016625104
1978	6.095871432529787
1979	6.165142698808534
1980	6.234413965087282
1981	6.30368523136603
1982	6.372956497644777
1983	6.442227763923524
1984	6.511499030202272
1985	6.58077029648102
1986	6.6500415627597675
1987	6.719312829038515
1988	6.733167082294264
1989	6.733167082294264
1990	6.733167082294264
1991	6.733167082294264
1992	6.733167082294264
1993	6.733167082294264
1994	6.719312829038515
1995	6.719312829038515
1996	6.719312829038515
1997	6.705458575782765
1998	6.705458575782765
1999	6.705458575782765
2000	6.788584095317263
2001	9.44195067885841
2002	12.608478802992519
2003	17.133139373787753
2004	19.91867553338875
2005	20.3937378775284
2006	23.41202549182599
2007	17.784981989470765
2008	19.01122194513716
2009	20.24064837905237
2010	21.894984760321417
2011	22.895954558049322
2012	20.388611803823775
2013	21.94028816846772
2014	21.94513715710723
2015	21.94513715710723
2016	21.94513715710723
2017	21.94513715710723
2018	21.94513715710723
2019	21.94513715710723
2020	21.94513715710723
2021	21.94513715710723