On and after the commencement of section 673, in determining under section 673(4) whether to release on parole a child or young person who is serving a sentence of imprisonment by reason of a direction given under Chapter 13 or Part 5.6 of Chapter 5 of the Children, Youth and Families Act 2005 (as in force immediately before that commencement), the Adult Parole Board may also take into account the periods which the child or young person has spent, before that commencement, in a youth residential centre or youth justice centre within the meaning of the Children, Youth and Families Act 2005 , as in force immediately before that commencement.