What percentage is GRS certified?

Could you please clarify what you mean by "GRS certified"? Are you referring to a specific certification program related to cryptocurrencies or finance? If so, it would be helpful to know the full name of the program or acronym to provide an accurate answer. However, in general, the percentage of entities that are certified by any given program will depend on various factors such as the requirements of the certification, the industry's awareness and adoption of the program, and the resources available to entities seeking certification. Without more specific information, it's difficult to give an exact percentage of GRS-certified entities.