how long is the maximum validity of multiple china visa?

I am from Philippines and I plan to visit China every now and then. Would like to know how many years is the maximum validity of a multiple entry china visa (e.g., 3, 4, 5 years)? Because there are some visas like Japan visa, which has up to five years validity for multiple entry visa...

Looking forward to your favorable response.

Thank you and regards,

Mark