By computing “learning rate” from the distribution of “vocabulary as a function of age” you are implicitly making a number of assumptions: the world is stationa

By computing “learning rate” from the distribution of “vocabulary as a function of age” you are implicitly making a number of assumptions: the world is stationary, and your sampling is homogenous across age. A word of caution could be useful before your conclusions: by looking at the graph one could also come to the conclusion that the quality of education is decreasing. Nonetheless, very interesting data. Thanks.