The CA dynamics are obtained by calculating the total of black cells at each CA step along the time axis.

You can see the four classes of CA rule behavior:

Class I CA tend to stabilize quickly to just one value with a short transitory state (e.g. rules 0 and 250).

Class II CA tend to vary between periodic values, becoming stable (e.g. rules 94 and 156).

Class III CA tend to keep behaving randomly (e.g. rule 30).

Class IV CA tend to have local random behavior (e.g. rule 110).

It is hard to tell the difference visually between classes III and IV, even with an algorithm.