Do the same measurement next year and the year after. The conclusion of this experiment will depend on the comparison of the number of berries from each section in each year. The number of berries in one year might vary greatly from one year to another. You might want to put a sign over your berry patches asking people to leave the berries alone because you are doing a scientific experiment there. You will have to do this experiment for several years to find the answer.
Some scientific experiments take many years.
A bear or birds harvesting in your patch one year might throw the conclusion off. You will have to pick the berries at the same time each year. When berries are over-ripe, the berry picker smashes many berries, and the count will be off of you are measuring by volume. This is an important experiment that needs to be done. We want to care for our berry patches, and we don't want unnecessary conflict between people.