The applications of the multiple regression technique in the prediction of supply quantity have been addressed in various research studies; for example, Gala et al. (2003) applied this technique to predict the supply quantity of olive in Spain by taking into consideration related environmental factors and found that the amount of pollen was an important factor in predicting the supply quantity of olive. Qian et al. (2008) also applied the multiple regression technique for forecasting the supply quantity from wheat production in Canada, and the results showed that the forecasting model that was based on the multiple regression technique gave the forecasting variance as 8-10%, when compared with the mean forecasting values.