Too few of us comprehend what goes into “RATES” to see how they are misleading, fictional and false indicators of reality. Essentially, no rate is constant and unchanging. Each rate is related and limited to its context; to the environment; to the time period; to the flux of what is being measured; to the underlying change taking place. We can speak of the rate of flow of a river, which flow is dependent upon the weather, the season, the absorbency of the lands being watered, the changes in the contours and contents of river beds, etc. We can speak of rates of acceptance of students at colleges and universities, but which rates vary by race, by socio-economic background; by decade; by SAT scores; cumulative averages, by nepotism, by what is in vogue for accepting students in universities; by fads and trends, etc., etc. A rate is but a snapshot of a particular situation at a particular time and thus cannot be generalized to all slightly similar situations. Rates change, in part, even because they change, and because they are noticed; and reacted to and thus changed more.
Moreover, those who heed and attend rates, tend to reify them as if they were as real as Pi (T) i.e. 3.14159,26535,89793, 23846. ... Rates are neither made in heaven nor in nature, but the result of one's measurement at a particular time and place but which becomes revered as some separate reality and indicator about the universe. We may learn, for instance, that a genetic mutation occurs once in EVERY 50 million reproductions, which may, be a rough average for a drosophila (fruit fly) but not for corn nor an anopheles mosquito.
In a sense, we are but fools to accept any “quote” as to a rate without asking questions and learning more of the particulars, sampling, context, etc., etc.