Premise: Why -- on the last point, it's -- I've counted that as zero. The reason I've counted it as zero is it seems to me that the added value, incentive value to produce between life plus 50, or life plus 70, is zero. It's carried out, as the economists do, to three decimal points, divide by 100 for the probability of your ever having such a work, and you get virtually zero, no difference between this and a perpetual copyright.
Hypothesis: The writer of this context made every attempt to use clear, concise language and reduce the amount of arbitrary numerical references - this was simply the best he or she could do, and on the inside, he or she feels terrible for the poor worker having to read this for a buck.