“When considering the relevant adult guideline, the court may feel it appropriate to apply a sentence broadly within the region of half to two thirds of the adult sentence for those aged 15 – 17 and allow a greater reduction for those aged under 15. This is only a rough guide and must not be applied mechanistically. In most cases when considering the appropriate reduction from the adult sentence the emotional and developmental age and maturity of the child or young person is of at least equal importance as their chronological age. This reduction should be applied before any reduction for a plea of guilty.”