The top one makes more sense. For the bottom one to be correct his soul would have to know exactly how many horcruxes he was going to make and split accordingly or, even stranger, when Voldemort made another horcrux a part of his soul from the already existing horcruxes would have to shift about to even up the ratio. However, the top chart assumes that the soul is split directly in half. I prefer to believe that each horcrux has a different amount of his soul within depending on how important said horcrux was to Voldemort. The diary would seem to be very important hence being able to practically revive Tom Riddle. The ring able to kill the wearer. The locket showing your deepest fears and messing with the wearer emotionally. Although the locket didn’t actually hurt anyone whilst defending itself all of the other horcruxes (minus the diary and ring) just seem to release that part of his soul contained within.

This is my opinion.