Year	% of land area
1961	2.928752464094621
1962	2.928752464094621
1963	2.928752464094621
1964	2.928752464094621
1965	2.942833004787384
1966	2.9569135454801465
1967	2.9569135454801465
1968	2.9569135454801465
1969	2.9569135454801465
1970	2.9850746268656714
1971	2.9850746268656714
1972	2.9850746268656714
1973	2.9991551675584343
1974	3.0132357082511967
1975	3.0273162489439596
1976	3.041396789636722
1977	3.055477330329485
1978	3.0695578710222473
1979	3.08363841171501
1980	3.13996057448606
1981	3.1962827372571105
1982	3.1962827372571105
1983	3.2666854407209236
1984	3.2666854407209236
1985	3.3089270627992113
1986	3.3511686848774995
1987	3.3511686848774995
1988	3.365249225570262
1989	3.365249225570262
1990	4.012954097437341
1991	4.364967614756407
1992	4.773303294846522
1993	4.998591945930723
1994	5.237961137707688
1995	5.392847085328077
1996	5.4491692480991265
1997	5.561813573641228
1998	5.604055195719516
1999	7.265558997465503
2000	7.702055758941144
2001	7.913263869332582
2002	7.969586032103633
2003	7.800619543790481
2004	7.800619543790481
2005	7.8428611658687695
2006	7.583779217121937
2007	7.499295972965362
2008	7.5978597578147
2009	5.461841734722613
2010	5.523796113770769
2011	5.4702900591382715
2012	5.304139678963672
2013	5.342157138834131
2014	5.385806814981695
2015	5.390030977189524
2016	5.404111517882287
2017	5.404111517882287
2018	5.3752464094621235
2019	5.49704308645452
2020	5.488594762038862
2021	5.513397634469164