This would vary from lake to lake. There are a lot of lakes that are overrun with small white crappie bc they multiply so fast and in large numbers. It vary's from lake to lake. I follow the 10 inch rule but there are days that i go take a bunch of "pan fryer's" out of the population bc at one time my home lake was overrun with small whites. We talked to a biologist with the game and fish and he told us that we needed to cull out a lot of the small whites, and that is what we did and in three or four years the fishery was 10X better. So there are different circumstances on diff lakes.
"Three-fourths of the Earth's surface is water, and one-fourth is land. It is quite clear that the good Lord intended us to spend triple the amount of time fishing as taking care of the lawn." - Chuck Clark :D