; and (B) the approximate amounts of those assets that are securities and have matured or expired; and (4) an assessment of— (A) what may have happened to the securities described in paragraph (3)(B); and (B) how the funds from maturing securities have been reinvested and the associated income flows. (b) Addressing uncertainty In preparing the report required by subsection (a), the Secretary shall— (1) where exact figures are uncertain, provide approximate ranges for those figures