Section 52. Upon the commencement of grand juror service, each grand juror shall complete and sign a financial questionnaire under the penalties of perjury. The completed questionnaire shall contain the financial data necessary for the determination of a daily compensation rate for the grand juror to be paid by the commonwealth for the fourth and subsequent days of grand juror service. The questionnaire shall indicate whether or not the grand juror is employed and, if so, the regular daily wages of the juror and the daily compensation the juror expects to receive from his employer while performing grand juror service. The questionnaire shall indicate travel expenses, if any, in excess of those ordinarily incurred by the juror, as a result of grand juror service. The questionnaire shall be in such form and shall contain such further information as deemed appropriate by the jury commissioner with the approval of the committee. The court, clerk of court, or assistant clerk may make inquiry to a grand juror's employer for the purpose of corroborating or clarifying information supplied by the grand juror or to ascertain relevant policies of the employer. The information supplied by grand jurors in these questionnaires shall be held confidential by the court, clerk of court, and assistant clerks. A grand juror shall notify the court if at any time during the period of his grand juror service the information provided by the juror in the financial question changes or becomes obsolete. A notice of this duty shall appear prominently on the questionnaire. The completed questionnaires shall be kept on file in the office of the clerk of court for one year after the discharge of the grand jury. Completed questionnaires shall not constitute a public record.