More than one tabulation occasionally appears for a single question. Why?
The purpose of additional tabulations is to provide the user more information. A hypothetical example may be the best way to explain. Suppose we asked small-business owners who export if they sell to customers in Canada. Then, suppose 33 percent say, yes – they do. That tells us that 33 percent of all small exporters have Canadian customers. Therefore, the first tabulation is 33 percent “yes” and 67 percent “no.” But not all small businesses export. So, the second question is, how many small-businesses export to Canada? That leads to the second tabulation. Since relatively few small businesses export, about 10 percent, the second tabulation might be 3 percent “yes” and 97 percent “no.” Three percent of American small businesses export to Canada. Two tabulations offer two sets of information.
