Year	% of land area
1990	1.8235077047236694
1991	1.8269067353866792
1992	1.8303025052889432
1993	1.833701529896448
1994	1.837100554503953
1995	1.8404995880191515
1996	1.8438986126266563
1997	1.8472976372341612
1998	1.8506966618416656
1999	1.8540956864491704
2000	1.8574947110566753
2001	1.875103618750696
2002	1.8927125264447167
2003	1.9103520644357286
2004	1.9279629718708078
2005	1.9455704445099666
2006	1.9631691419928328
2007	1.9807747090498524
2008	1.9983819934866418
2009	2.016441888334009
2010	2.034056325032463
2011	2.035530875124637
2012	2.03700578688751
2013	2.038516115086812
2014	2.0400132260105486
2015	2.041487267568222
2016	2.0413748197062054
2017	2.0433527807437386
2018	2.0447403144862832
2019	2.0481295393293615
2020	2.0508967195466066
2021	2.0540790067466523