District, county, etc. This would be the next smallest geographical breakdown. This may not be essential information for the more rural areas of the world. However, we do want to be sure we are getting sufficient penetration of the Gospel into the big cities. One of our challenges in evangelization, is to be sure that we are making enough efforts to proclaim the Gospel in the most understandable language.
Trade languages are better than nothing.
Mother tongue is best. This may not be crucial, as a category, to collect. HOW a person hears the Gospel is not nearly as important as the fact that he hears. We are interested, however, to keep pointing our evangelization efforts, not only to conversion, but to eventual incorporation into a local body of believers. Therefore, the more mass evangelism that we do, the greater the challenge to locate the interested listeners and readers, and help them take the next steps in discipleship.