I didn't keep track of my individual box/case breaks, but I have cracked 9 cases thus far and here are my numbers:
1- Daniel Radcliffe / Katie Leung (R)
1- DEP-Z1 - Richard Cubison
1- DEP-Z2 - Richard Trinder
1- DEP-Z3 - Tav MacDougall
1- Brendan Gleeson as Mad-Eye Moody (R)
3- Tom Felton as Draco Malfoy
1- Kathryn Hunter as Arabella Figg (R)
4- David Thewlis as Remus Lupin (R)
4- Helena Bonham Carter as Bellatrix L.
5- Harry Melling as Dudley Dursley
3- Jason Piper as Bane (R)
3- Sian Thomas as Amelia Bones (R)
9- Natalia Tena as Nymphadora Tonks
3- Timothy Bateson as the voice / Kreacher
4- Robert Hardy as Cornelius Fudge
Hope that helps with the number figuring
