What you wrote was not rude, you were just expressing your opinion. I had never seen data like this and I thought others might find it interesting, as I did.

   It is backward looking data, that may or may not have validity for the future. The authors were well aware of the limitations of the data, but they just wanted to see by looking back at season avg. prices, when there was a decline from year to year, how long did it take to reach the price before it declined. From the article:
" In each subperiod, we compare the season average price for each year with the season average price for the following year. If the following year's price is lower, we define this as a year-to-year price decline. We then look ahead, year by year, until we find a season average price that is equal to or higher than the beginning value.

For example, the season average price for 1866 was 65.7 cents per bushel, and for 1867 it was 78.1 cents. But the season average price for 1868 was just 61.7 cents, so from 1867 to 1868 there was a year-to-year price decline (78.1 cents for 1867 vs. 61.7 cents for 1868). We then examine the prices for 1869, 1870, and so on until we find a season average price of at least 78.1 cents - the value for 1867 - and then count the number of years between the time they fell below 78.1 cents and when they recovered to at least 78.1 cents"