The damage for the spell delayed blast fireball is listed as:
The spell’s base damage is 12d6. If at the end of your turn the bead has not yet detonated, the damage increases by 1d6.
The spell's duration is "Concentration, up to 1 minute".
Does this damage increase repeat on each of your turns throughout the spell's duration?
Or does it only apply to the turn when you cast the spell?