Year	% of land area
1961	9.433962264150944
1962	9.615384615384617
1963	9.796806966618288
1964	9.978229317851959
1965	10.159651669085632
1966	10.341074020319303
1967	10.522496371552975
1968	10.703918722786646
1969	10.88534107402032
1970	11.06676342525399
1971	11.248185776487665
1972	11.46589259796807
1973	11.429608127721336
1974	11.429608127721336
1975	11.429608127721336
1976	11.429608127721336
1977	11.429608127721336
1978	11.429608127721336
1979	11.429608127721336
1980	11.611030478955007
1981	11.611030478955007
1982	11.611030478955007
1983	11.611030478955007
1984	11.611030478955007
1985	11.611030478955007
1986	11.611030478955007
1987	11.611030478955007
1988	11.611030478955007
1989	11.611030478955007
1990	11.611030478955007
1991	11.611030478955007
1992	10.88534107402032
1993	10.88534107402032
1994	10.88534107402032
1995	10.88534107402032
1996	10.88534107402032
1997	10.88534107402032
1998	10.88534107402032
1999	10.88534107402032
2000	10.88534107402032
2001	10.159651669085632
2002	10.159651669085632
2003	10.159651669085632
2004	10.159651669085632
2005	10.159651669085632
2006	10.159651669085632
2007	10.159651669085632
2008	10.159651669085632
2009	10.88534107402032
2010	11.393323657474602
2011	12.300435413642962
2012	12.844702467343977
2013	14.44121915820029
2014	14.44121915820029
2015	14.44121915820029
2016	14.44121915820029
2017	12.336719883889694
2018	11.79245283018868
2019	10.88534107402032
2020	10.88534107402032
2021	10.88534107402032