1. Go to Analysis > Information Library.  Click Add an ad-hoc query.  Select the source view of Constituents and click ok.
  2. On the left, click on the plus sign next to the Attributes folder.
  3. Click on the name of the attribute on the left.
  4. In the middle, click on Value and move to Include Records Where.
  5. Set the criteria to Not Blank.
  6. Go to the Set Save Options.  Name and save your query.