Agents

HI All... I am having trouble trying to find out what is a legitimate, or at least industry standard percentage that an agent in the performing arts might take.

Can anyone tell me where I might find an industry standard documents that would list the recommended amount, or failing that, a list of examples and percentages?

Would love to hear from anyone who is dealling with an agent, and who would be willing to disclose the amount that they pay.

Thanks for you help!