619.7  Mitigating facts.
  In any action brought to recover damages for an injury to person, character, or property, the defendant may set forth, in a distinct division of the defendant’s answer, any facts, of which evidence is legally admissible, to mitigate or otherwise reduce the damages, whether a complete defense or justification be pleaded or not, and the defendant may give in evidence the mitigating circumstances, whether the defendant proves the defense or justification or not.
[R60, §2929; C73, §2682; C97, §3593; C24, 27, 31, 35, 39, §11172; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §619.7]