Historical clue formulations

• Packs of zombies — 2025-10-10
• Throngs — 2023-05-30
• Packs — 2021-05-29
• Swarms — 2014-09-28
• Large numbers — 2010-04-10
• Lots — 2005-05-05
• Big numbers — 2002-02-23
• Mobs — 1996-05-26