Year	% of land area
1990	59.72542187500001
1991	59.63552265625
1992	59.5456234375
1993	59.45572421875001
1994	59.36582500000001
1995	59.275925781249995
1996	59.186026562500004
1997	59.096127343750005
1998	59.00622812499999
1999	58.91632890625
2000	58.8264296875
2001	58.72892734375
2002	58.63142500000001
2003	58.53392265624999
2004	58.436420312500005
2005	58.33891796875
2006	58.241415625
2007	58.14391328124999
2008	58.046410937500006
2009	57.948908593750005
2010	57.851406250000004
2011	57.717770312499994
2012	57.584134375000005
2013	57.450498437499995
2014	57.3168625
2015	57.1832265625
2016	57.03928125000001
2017	56.90217187500001
2018	56.77815625
2019	56.643125000000005
2020	56.5081015625
2021	56.373072890625