Hi, funnel chart is most commoly used for show distribution of tasks with different stages, a usaul example is a selling process, ie: Leads listed -> Leads contacted by company -> leads answering to contact -> ofeer sent -> offer accepted. Each stage can be a % of the previuos task: leads listed is 100%, after contacted perecentage reduces to 75% ... and each step (can) reduce percentage to the final % of offer accepted.
