Historical clue formulations

• "I feel that way, too" — 2016-07-10
• Copycat's comment — 2015-11-06
• "Right back at cha!" — 2011-10-30
• "I'm with you" — 2011-06-17
• "That makes two of us" — 2010-09-03
• "Me too" — 2007-03-11
• Concurring comment — 2006-02-04
• "Likewise" — 2001-01-05
• "Ditto" — 1997-08-24
• "Ditto" — 1997-05-30