The alpine area fluctuates greatly because of regional fluctuations in tree lines. The attrition rate fluctuates, but averages at about 80 percent. An exchange rate between two currencies fluctuates over time. Although the average rainfall is around , it fluctuates greatly. Their weight fluctuates seasonally up to . It fluctuates with time and its value is usually time averaged. This count fluctuates throughout the day, seasonally, and during menstruation. Finn subsequently wakes up on an island where the weather drastically fluctuates. Annual temperature fluctuates around , and annual rainfall around . Population size fluctuates at differing rates in differing regions. The ocean temperature around the island fluctuates between . In thermal equilibrium a system's energy only fluctuates within a small range. In General Theory pricing most usually fluctuates. The mean temperature in July fluctuates from . It looks like a static picture, but in reality the energy fluctuates, or flickers.