1. Create your selection query, using registrant query  
  2. Go to the set save option tab of the query and check the button to create a selection
  3. name and save your query 
  4. Go to analysis
  5. Click information library
  6. Click the KPI tab
  7. Click Add
  8. Expand the selections folder
  9. Select total record count in selection
  10. Click okay
  11. On the general tab name the KPI
  12. On the criteria tab click the magnifying glass  search for your selection
  13. Use the goal tab to establish the number of desired registrants 
  14. Click save
  15. Click the expand button next to your KPI
  16. Click Update KPI value
  17. Option- To set up a job schedule, click the name of your KPI and click the job schedule tab, click add, then select the frequency and times you what the KPI to update. 
  18. Click save