Year	% of land area
1990	0.0440102466221307
1991	0.04555728564970617
1992	0.04710432467728163
1993	0.0486513637048571
1994	0.05019840273243257
1995	0.05174544176000804
1996	0.05329248078758351
1997	0.054839519815158964
1998	0.05638655884273444
1999	0.05793359787030992
2000	0.05948063689788538
2001	0.06012657592043799
2002	0.06077251494299061
2003	0.06141845396554323
2004	0.06206439298809584
2005	0.06271033201064845
2006	0.06335627103320106
2007	0.06400221005575368
2008	0.0646481490783063
2009	0.0652940881008589
2010	0.06594002712341153
2011	0.06248028529810638
2012	0.05902054347280125
2013	0.05556080164749611
2014	0.052101059822190966
2015	0.04864131799688583
2016	0.0451855944547692
2017	0.0451855944547692
2018	0.0451855944547692
2019	0.0451855944547692
2020	0.0451855944547692
2021	0.0451855944547692