Mitigating circumstances shall include, but not be limited to. the following:
(1) The defendant has no significant history of prior criminal activity;
(2) The capital offense was committed while the defendant was under the influence of extreme mental or emotional disturbance;
(3) The victim was a participant in the defendant's conduct or consented to it;
(4) The defendant was an accomplice in the capital offense committed by another person and his participation was relatively minor;
(5) The defendant acted under extreme duress or under the substantial domination of another person;
(6) The capacity of the defendant to appreciate the criminality of his conduct or to conform his conduct to the requirements of law was substantially impaired; and
(7) The age of the defendant at the time of the crime.