Historical clue formulations

• Flood — 2016-03-17
• Swamp — 2015-09-25
• Overwhelm — 2014-12-03
• Overwhelm — 2013-01-23
• Submerge — 2010-11-14
• Overwhelm — 2003-04-08
• Deluge — 2002-07-08
• Flood — 2001-07-02
• Swamp — 1996-10-12
• Swamp — 1996-09-14
• Swamp — 1995-03-16