For some countries, data was not accounted for, so they are not counted as mines or answers. Data as of 2006. Please also note that I personally do not hold the opinion of the source and facts on this quiz are merely based upon the source data.
For 104 of the 185 nations, no studies were available. In those cases, the authors have used an estimated value by taking averages of the IQs of neighboring or comparable nations. For example, the authors arrived at a figure of 84 for El Salvador by averaging their calculations of 79 for Guatemala and 88 for Colombia.