Historical clue formulations

• Apartment sharer — 2017-10-10
• Dorm assignment — 2012-12-18
• Joint letter? — 2009-10-09
• School pal, maybe — 2004-10-17
• Utility bill sharer — 2004-01-21
• Unwelcome snorer — 2002-11-17
• School buddy, maybe — 2001-07-01
• Telephone bill splitter — 1999-10-14
• Dorm companion — 1998-03-08