Or 165, 175, 185, 195, 205, 225, 265 and have strict weight cutting rules / rehydration levels.With all the champ-champ fights, the UFC definitely needs a new division. 155 is too stacked. As has been said before:
Add 165
170 --> 175
185 --> 190
Problem solved. Now you have an additional championship so you can have more champ-champ fights.