Year	% of land area
1990	70.61538461538461
1991	70.87179487179486
1992	71.12820512820512
1993	71.38461538461539
1994	71.64102564102564
1995	71.89743589743588
1996	72.15384615384615
1997	72.41025641025641
1998	72.66666666666666
1999	72.9230769230769
2000	73.17948717948717
2001	73.17948717948717
2002	73.17948717948717
2003	73.17948717948717
2004	73.17948717948717
2005	73.17948717948717
2006	73.17948717948717
2007	73.17948717948717
2008	73.17948717948717
2009	73.17948717948717
2010	73.17948717948717
2011	73.17948717948717
2012	73.17948717948717
2013	73.17948717948717
2014	73.17948717948717
2015	73.17948717948717
2016	73.17948717948717
2017	73.17948717948717
2018	73.17948717948717
2019	73.17948717948717
2020	73.17948717948717
2021	73.17948717948717