Year	% of total
1970	7.0537083052082155
1971	7.021734216960662
1972	7.0376001757579045
1973	6.967422193792719
1974	7.421433072321718
1975	7.361578116996211
1976	7.2429655714290835
1977	7.0102640052245455
1978	6.988113961810308
1979	6.73629804835177
1980	6.085617437401485
1981	6.177965386810358
1982	6.1317275507353
1983	5.923515367185061
1984	6.0769089978695625
1985	6.0918912344069005
1986	6.185790839289224
1987	5.580605018186175
1988	5.807293800644724
1989	5.876361849457027
1990	11.895399763434673
1991	11.634383703101042
1992	11.438512223659092
1993	11.768435736478345
1994	11.286935881440005
1995	9.974390079525543
1996	9.368537852423463
1997	10.114736756448856
1998	9.91866903330066
1999	9.543884599756197
2000	9.772585992540407
2001	9.764197085929053
2002	9.386770389699908
2003	9.403135196133748
2004	9.168986272690505
2005	9.049498937139386
2006	9.128111856314652
2007	9.267683525109268
2008	9.256625727213963