Year % of land area 1961 2.898550724637681 1962 2.898550724637681 1963 2.898550724637681 1964 2.898550724637681 1965 2.898550724637681 1966 2.898550724637681 1967 2.898550724637681 1968 2.898550724637681 1969 2.898550724637681 1970 2.898550724637681 1971 2.898550724637681 1972 2.898550724637681 1973 2.898550724637681 1974 2.898550724637681 1975 2.898550724637681 1976 2.898550724637681 1977 2.898550724637681 1978 2.898550724637681 1979 2.898550724637681 1980 2.898550724637681 1981 2.898550724637681 1982 2.898550724637681 1983 2.898550724637681 1984 2.898550724637681 1985 2.898550724637681 1986 2.898550724637681 1987 2.898550724637681 1988 2.898550724637681 1989 2.898550724637681 1990 2.898550724637681 1991 2.898550724637681 1992 2.8169014084507045 1993 2.8169014084507045 1994 2.8169014084507045 1995 2.8169014084507045 1996 2.8169014084507045 1997 2.8169014084507045 1998 2.8169014084507045 1999 2.8169014084507045 2000 2.8309859154929575 2001 2.8309859154929575 2002 2.845070422535211 2003 2.8055555555555554 2004 2.780821917808219 2005 2.7432432432432434 2006 2.7567567567567566 2007 2.7199999999999998 2008 2.697368421052632 2009 2.697368421052632 2010 2.7034120734908136 2011 2.6857887874837028 2012 2.688311688311688 2013 2.688311688311688 2014 2.6977950713359276 2015 2.6735218508997427 2016 2.682926829268293 2017 2.6794871794871793 2018 2.6992287917737787 2019 2.6923076923076925 2020 2.67515923566879 2021 2.6582278481012658