Greg Giuliani, of Seattle Tree Fruit Society, recently pointed out: "A mid-sized apple tree will produce close to the same weight in fruit whether it has, for example, 200 or 50 apples on it."
This means that it's time to thin your fruit! Too many fruits on a tree means fewer cells for each fruit, and so they all stay smaller. Removing some fruits means that those remaining will be larger. Thinning also helps prevent the boom and bust cycle in which a tree produces heavily one year and little the next. To thin the tree, remove the small fruits and aim for an even spacing along the branch. Apples, pears, Asian pears and peaches almost always need heavy thinning.