[Yo-Yo]

Asteroids Don’t Break Up Like You Think They Do: Study

Everybody knows that the big ones break up into two medium size pieces. The medium ones break up into three small pieces. The small pieces vaporize.

[Flatus I. Maximus]

...and the trick is to zap ‘em until there’s only one small piece floating around, and then wait for the flying saucers to come out and pick them off as they appear.

[Dr. Sivana]

Everybody knows that the big ones break up into two medium size pieces. The medium ones break up into three small pieces. The small pieces vaporize.

Ah, but look at your screen shot. The rocks DON'T break up from collisions with each other, only from collision with a spaceship or a shot fired from said ship. BTW, if that is your work (97,310 with six ships remaining), you are good.