the Board shall be required to approve a change in the assessment rate. (B) Limitation on increases An increase or decrease in the assessment rate with respect to concrete masonry products may not exceed $0.01 per concrete masonry unit sold. (C) Maximum rate The assessment rate shall not be in excess of $0.05 per concrete masonry unit. (D) Limitation on frequency of changes The assessment rate may not be increased or decreased more than once annually. (d) Late-Payment and interest charges (1) In general Late-payment and interest charges may be levied on each person subject to the order who fails to remit an assessment in accordance with subsection (b) . (2) Rate The rate for late-payment and interest charges shall be specified by the Secretary. (e) Investment of assessments Pending disbursement of assessments under a budget approved by the Secretary, the Board may invest assessments collected under this section in— (1) obligations of the United States or any agency of the United States