To make your life easier, I've already sort the past year questions according to the topics.
It is from 2005 - 2011.
Kindly click and save the link below for your reference.
Past Year Questions :
1. PMR 2005-2011 : Indices
2. PMR 2005-2011 : Algebraic Expressions III
3. PMR 2005-2011 : Algebraic Formulae