A printing press has a two-station binding line, in which the first station punches holes in the pages and the second station installs the binders. On average, the punching machine can process 15,000 pages per hour, while the binder can process 10,000 pages per hour. The shop receives work that requires punching and binding at a rate of 8,000 pages per hour. It also takes punch-only jobs at a speed of 5,000 pages per hour. Which station is the bottleneck on this line and why?