column 1: smoking index
column 2: mortality index

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% 
%                                                                             
% The smoking index is the ratio of the average number of cigarettes  smoked 
% per day by men in the particular occupational group                        
% to the average number of cigarettes smoked per day by all men.             
% The mortality index is the ratio of the rate of deaths from lung cancer    
% among men in the particular occupational group to the rate of deaths from  
% lung cancer among all men.                                                 
%                                                                            
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