I opened a few boxes on tailed beasts attack and got like 3 tailed beasts, so I impulsively clicked open all and sunk all but 20 of my coupons, but that's fine. Satisfaction? Yes. Regret? Definitely.

And I thought I'd just... share the ratios. Not sure if it'll be useful at all, but... well, it's here.

Out of 81 boxes:

32 5s

23 10s

10 15s

7 20s

and of course, 9 tailed beasts.

I'll add a picture later. Not sure if it's always this many of each, but not like I have the coupons to try again anyways...