Passage Summary: Even though full-fare ticket prices haven't changed, way more people are buying discount tickets now than last year, leading to a lower average price per person.

Conclusion: The average price paid for a coach ticket on this route is lower today than it was one year ago when adjusted for inflation.

Reasoning: The price of a full-fare ticket has remained constant, but the proportion of travelers using discount tickets has increased from 50 percent to 90 percent.

Analysis: This argument relies on a mathematical gap regarding the price of the discount tickets themselves. We know the ratio of discount to full-fare has shifted heavily toward the cheaper option, and we know the 'expensive' option's price is stable. However, if the price of a 'discount' ticket rose dramatically over the last year, the average could still be higher despite the shift in volume. To make this conclusion follow logically, we must assume that the price of a discount ticket today is not significantly higher than it was a year ago.