What I was getting at was that maybe typing speed is not the bottleneck. You have to look at how much time the clerk spends typing vs. eg. talking to the customer, clarifying details, explaining the process, reviewing documents, etc. If they spend 5% of their time typing, then even speeding up their typing speed by a factor of 5 will only lead to a 4% speedup, assuming they are fully booked (ie. no wait time between clients).