Individual samples are subject to the following limitations, unless otherwise specified in § 51.1820. Individual samples shall have not more than one and one-half times a specified tolerance of 10 percent or more, and not more than double a specified tolerance of less than 10 percent: Provided, that at least one decayed or wormy fruit may be permitted in any sample: And provided further, that the averages for the entire lot are within the tolerances specified for the grade.