Place apples and water in an 8 inch baking dish. Combine flour, oatmeal, brown sugar and cinnamon. Add margarine and blend until crumbly. Spread over apples. Bake at 350 degrees for 45 minutes. Spoon Apple Crisp equally into eight dessert dishes, and top with frozen yogurt. Serves 8. Nutritional analysis per serving: Calories, 456; Protein, 9 g; Carbohydrates, 80 g; Fiber, 5 g; Sodium, 337 mg; Cholesterol, 4 mg; Fat, 14 g (27% of calories from fat).