Frequency of exceedance any peak exceeding is . Its complement, is the probability of exceedance, the probability that has been exceeded at least once by time . This probability can be useful to estimate whether an extreme event will occur during a specified time period, such as the lifespan of a structure or the duration of an operation. If is small, for example for the frequency of a rare event occurring in a short time period, then Under this assumption, the frequency of exceedance is equal to the probability of exceedance per unit time, , and the probability of exceedance can be computed
Edible protein per unit area of land usable protein per unit area than any other major vegetable or grain crop, except for hemp which can produce up to . They produce 5 to 10 times more protein per unit area than land set aside for grazing animals to make milk, and up to 15 times more protein per unit area than land set aside for meat production. Selected averages as computed in the 1970s. Edible protein per unit area of land Edible protein per unit area of land is a measure of agricultural productivity. This measure for various major foodstuffs is shown in the chart below. Values