Historical clue formulations

• Abstain — 2016-01-31
• Recuse oneself from, say — 2011-11-11
• Skip, in a way — 2002-03-22
• Skip — 2002-01-05
• Not participate — 2000-02-16
• Not participate in — 1999-05-02
• Not participate in — 1998-07-08
• Skip — 1996-12-14
• Not take part in — 1996-10-30