If a student is appearing twice within this SKY list it could be due to duplicate addresses being listed as the Preferred Address on the student's profile. 

To Remove the Duplicate: 
  1. Navigate to Enrollment Management > People Finder > [Name of Student]
  2. Select the Contact Card tab
  3. Scroll down to the Address block
  4. Remove the duplicate Preferred Address by selecting the Trash Bin Icon next to the address
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