Gantt not redering progress

Hi, gantt is not rendereing progress, xml data is shown below, is this correct ?
What can be the problem?

WBS Secondo Step parte A, (Mirahili, Akram) WBS Secondo Step parte B, (Derossi, Alberto) WBS Terzo Step, (Neri, Alberto) WBS primo Step

the progress is expected to be a value between 0 and 1. Values greater than 1 are handled as 1 (100%). i.e. both 86.2 and 70 are considered as 100%.
So when the gantt renders your dataset, it displays two tasks with zero progress, and 2 tasks with 100% progress … properties