Historical clue formulations

• Do some work as a teaching assistant, maybe — 2024-04-03
• A, B, C or D, but rarely E — 2023-10-15
• A, B or C, or first, second or third — 2020-08-04
• *Kind of average — 2019-05-23
• A+ or B- — 2019-02-19
• A+ or C- — 2018-08-06
• Leave one's mark? — 2017-11-19
• Incline — 2016-11-18
• Slope — 2012-06-24
• Learning level — 2007-08-12
• Any number from 1 to 12 — 2007-04-13
• Steepness — 2007-04-10
• Exam mark — 2004-05-31
• Rank — 2003-09-18
• Letter from a teacher — 2003-08-12
• Mark — 2002-04-11
• A+ or C- — 2001-06-11
• See 90-Across — 2000-08-27
• A+ or C– — 2000-02-14
• A+ or C- — 1999-05-17
• A, B or C — 1997-11-06
• School division — 1997-04-22
• D or F, but rarely E — 1996-02-08
• Year in school — 1995-12-24
• Flatten — 1994-06-11