It can flower every year, depending on how good the growing conditions are. Usually, all you need to do is cut off the spent flower spike, as close to the new rosette as you can manage. If it definitely needs some size control, you can cut it back to a stump, and you will get one or two new rosettes at the top of the stump, probably plus some shoots at the base. A light feeding with Growmore will help it to recover from pruning, too.