Bob here is where you jammed up, IMHO
People who have a lot of money think it is gauche to talk about income, and how much they are worth in general. That's just how it is. The surveys I have taken say something like this.
Annual Household Income: 0-$!2,000 $13,000-$36,000 $37,000-$58,000 $59,000-$84,000 Over $84,000 Net Worth: Under $12,000 Under $36,000 etc.
This way you just check the box and don't have to get technical. It doesn't seem so personal for people when they check boxes instead of filling in numbers. I would think they do this as not to get people all riled up, or offended when talking about personal finance. Once again IMHO