Year	% of land area
1961	1.3993965102549526
1962	1.5096659422083556
1963	1.3031461521931587
1964	1.265692208512591
1965	1.2276105451055332
1966	1.2096159129461543
1967	1.1889011619719858
1968	1.2895455581192095
1969	1.2949857957487891
1970	1.2949857957487891
1971	1.3573392885801252
1972	1.357967008306615
1973	1.405715555501618
1974	1.4101305175779308
1975	1.4128506363927207
1976	1.4140433038730515
1977	1.4157172231436916
1978	1.4119509047847518
1979	1.4144617836907116
1980	1.4795353953368375
1981	1.5314268927266743
1982	1.535402450994444
1983	1.5983836635522701
1984	1.6029869415465299
1985	1.6067532599054697
1986	1.6544599591187066
1987	1.7551043552659302
1988	1.7574059942630602
1989	1.7622185121661498
1990	1.8032295342968274
1991	1.8762542624784928
1992	1.9419346698602256
1993	2.0379548640223066
1994	2.0700168472931177
1995	2.123429471866697
1996	2.2418005649291324
1997	2.246180022965962
1998	2.276752411845072
1999	2.40560067724442
2000	2.4194416914782835
2001	2.4979937686349034
2002	2.5149655431072597
2003	2.5973100785101715
2004	2.675150237468578
2005	2.738240437380671
2006	2.8584891008011617
2007	2.953438803658896
2008	3.0051266551483384
2009	3.0943542235954413
2010	3.185405329382196
2011	3.2222114393641346
2012	3.316301774050309
2013	3.3873568496988122
2014	3.4014001832340623
2015	3.4118357361329776
2016	3.4291324163963575
2017	3.4437021674548656
2018	3.5184619938601176
2019	3.5302013827743997
2020	3.5979178720870753
2021	3.604102202879592