Historical clue formulations

• Dunderheads — 2025-03-23
• Ding-dongs — 2024-12-25
• Dodos — 2021-10-10
• No-brainers? — 2016-10-15
• Nincompoops — 2015-10-19
• Thick bunch? — 2013-12-08
• Jerks — 2002-04-24
• Ninnies — 2000-10-22
• Dunderheads — 1997-06-01