How can you improve your chances of getting inform players on FIFA 12 ultimate team

1418 gold players
11-15 gold in forms per week <13 ave.>
premium gold pack 12 items
-3 rares
-1-5 players <ave. 3>
62.5% chance 1 player will be rare [(3/12)*3)/12]
9.16784203% of gold players are inform
0.57299012% chance of inform in premium gold pack
this is further limited by the fact that only 160 of each inform players are released

i am not totally sure these calculations are complete as I was unable to find how many rare gold players there are without prior released informs.

(this is fifa 13 i am answering for)