Why does the daily number matter to you? The Law of Large Numbers - as applied to most Dispatch jobs means there will not be a predictable daily average.
Isn;t your real question "How to real life dispatchers keep their emotional Intelligence and self-confidence at its peak so they can Give their BEST to each and every incomeing call?" Then ask yourelf if you have what it takes to be grace and effeciency, acting as if there is no pressure so as to keep everyone invovled calm and communicating correctly and accurately. If you don;t have what it takes NOW do this job, what can help you build the ability? SKy Diving? Hang Gliding? Minding4 year old triplet boys on your own for a full 24 hours?
IF you want this career, you will figure it out on your own. No one can prescribe what you need but you.