Biosecurity level expected returns.

Expected Returns in experimental dollars for each level of biosecurity adopted. The probability of infection (pi) is estimated using several hundred trials at each specified biosecurity level. Recall, the the probability of infection depends on the infection rate and distance to each infected facility.

各已采用的生物安全（biosecurity）等级对应的、以实验美元为计价单位的预期收益。感染概率（π）通过在各指定生物安全等级下开展的数百次试验估算得出。需注意，感染概率取决于感染率以及与各受感染设施之间的距离。