What is sufficient evidence to determine that one of the primary activities of a gang is committing one or more of the criminal acts enumerated in subdivision (e) of the California Gang Act?

the commission of one or more of the criminal acts enumerated in subdivision (e). Evidence of both past offenses and the currently charged offenses may be considered in determining whether one of the primary activities of the gang is committing one or more of the offenses enumerated in the statute. (People v. Sengpadychith (2001) 26 Cal.4th 316, 323, 109 Cal.Rptr.2d 851, 27 P.3d 739.) Sufficient proof of the gang's primary activities might consist of evidence that the group's members consistently and repeatedly have committed criminal activity listed in the gang statute. Also sufficient might be expert testimony.... (Id. at p. 324, 109 Cal.Rptr.2d 851, 27 P.3d 739.)