Historical clue formulations

• Very rarely — 2021-02-16
• Occasionally — 2006-02-21
• Sometimes — 2005-05-24
• Rarely — 2000-11-14
• Practically never — 2000-05-30
• Infrequently — 1995-08-29
• Rarely — 1994-10-24
• Rarely — 1994-08-29