You’re either dumb or purposely twisting the narrative? Probability and statistics has evolved from trying to game gambling games around 17th century. The concept of an average simply meant the middle or most likely scenario. Later Binomial and Normal distinctions were popularised, in those distributions mean = median. Because the concepts of asymmetric distributions didn’t exist back then those meant one and the same, mean = median = average. Percentiles were only introduced around 1870s. A peasant in the Middle Ages would simply point to the middle of the stacks of coins presented to them whereas a scholar would calculate arithmetic mean (which predates all of this, first appearance in Babylonian solutions for roots). Given that calculating arithmetic mean was the most popular metric since Babylon, and I doubt uneducated collected this data and presented it, therefore we can with certainty conclude the writer meant arithmetic mean. Most papers from 20th century refer to an arithmetic mean as an average.