Actual experience shows that on the average the price of wheat and other nonperishable crops remains the same all year round except for an allowance for storage, interest and insurance charges.
This fighting hypothesis, where an imbalance in the population results in an advantage for left-handed fighters or athletes, is an example of negative frequency-dependent selection.
The vaccines given to sleep-deprived men, therefore, still provided protection but the effect was less potent from the start and lasted for less time, on average.
The average quantity of all sorts of grain exported from Great Britain does not, according to the same author, exceed the one-and-thirtieth part of the annual produce.
The problem up here is not that it receives a low amount of rain on average but that it receives that rain largely all at once and over ridiculously variable periods of time.
There remains a shocking imbalance in the global distribution of vaccines. On average, in high-income countries, almost one in four people has received a vaccine. In low-income countries, it's one in more than 500.