How have courts interpreted "age" as a sentencing factor in sentencing decisions?

have long held that "age" as statutory sentencing factor includes "any age-related matter suggested by the evidence or by common experience or morality that might reasonably inform the choice of penalty. Accordingly, either counsel may argue any such age-related inference in every case." (People v. Lucky (1988) 45 Cal.3d 259, 302; see also, e.g., People v. Carrington, supra, 47 Cal.4th at p. 202.) Defendant did not argue below that the jury should consider that he was 19 at the time of the crimes. Nevertheless, the jury was free to disregard the prosecutor's less than coherent argument on this factor and view his relative youth as a mitigating factor.