This means that the FBI statistics represent the most conservative estimate of anti-Muslim hate. [definitional]
One report by the Bureau of Justice Statistics indicates that the actual number of hate crimes in the United States is anywhere from nineteen to thirty-one times higher than the FBI’s numbers. Approximately 56 percent of hate crimes are not reported to the police, and more than half that are reported are mislabeled as other types of crimes. This means that the FBI statistics represent the most conservative estimate of anti-Muslim hate crimes.
Green, Todd H, The Fear of Islam_ An Intro…, loc. 594