How often should u have to change a serpentine belt on 2004 Dodge Caravan? on 2004 Dodge Caravan

Serpentine belt replaced 2009, idle pulley and serpentine belt 2010, now 2013 belt replaced again yet loud noise still there!

Asked by for the 2004 Dodge Caravan
Why is it being replaced? Splitting, coming off, breaking or a shop keeps telling you it needs replaced?
I've owned 4 Chrysler mini vans with a 3.3 and replaced the belt when bought and never after that, at least 5years owned on all