Historical clue formulations

• Spacey sort — 2023-12-31
• Scatterbrained sort — 2022-09-05
• Airhead — 2018-10-23
• Airhead — 2015-12-03
• Space cadet — 2014-01-19
• Scatterbrain — 2012-10-13
• Airhead — 2012-10-02
• Airhead — 2011-10-31
• Scatterbrain — 2009-04-09
• Airhead — 2005-11-28
• Airhead — 2000-11-22
• Airhead — 1999-06-03