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variable utilized in the study. 

The average age of the sampled individuals is 44.84 years with a standard deviation of 18.59 years, but in Table 5 we report the mean and standard deviation of the logarithm of age variable used in the study. Information on family income in the survey is recorded as one of the 9 income categories: < 10 k , 10 k − 20 k , 20 k − 30 k , 30 k − 40 k , 40 k − 50 k , 50 k − 75 k , 75 k − 100 k , 100 k − 150 k and > 150 k , where k denotes a thousand dollars and $5,000 

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