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
Oh Dear! What Can the Matter Be? he'd buy me a fairing should please me, And then for a kiss, oh! he vowed he would tease me, He promised he'd bring me a bunch of blue ribbons, To tie up my bonny brown hair. </poem> Cohen's "Folk Music" gives a different version of the lyrics: <poem> O dear, what can the matter be? O dear, what can the matter be? O dear, what can the matter be? Johnny's so long at the fair. He promised he'd bring me a bunch of blue ribbons. He promised he'd bring me a bunch of blue ribbons. He promised he'd bring