Year	% of land area
1992	5.971418143899896
1993	5.9946079249217945
1994	6.017797184567257
1995	6.040986965589156
1996	6.064176225234619
1997	6.087365484880083
1998	6.110555265901981
1999	6.133745046923879
2000	6.156934306569343
2001	6.182367049009385
2002	6.2077997914494265
2003	6.233232533889469
2004	6.25866527632951
2005	6.284098018769551
2006	6.309530761209594
2007	6.334963503649635
2008	6.360396246089676
2009	6.385828988529719
2010	6.41126173096976
2011	6.434337851929092
2012	6.457413972888425
2013	6.4804900938477585
2014	6.503566214807091
2015	6.526642335766423
2016	6.549739311783107
2017	6.5728060479666315
2018	6.6678832116788325
2019	6.762982273201251
2020	6.85808133472367
2021	6.953180396246091