Historical clue formulations

• Like a runner-up, often — 2009-09-05
• Less apt to learn — 2008-02-08
• Not as busy — 2007-11-11
• Ritardando, musically — 2003-10-26
• Like rail vis-à-vis air — 2000-06-11
• Largo, vis-à-vis presto — 1998-07-12