the aggregate amount distributed from an individual retirement plan shall be treated as includible in gross income to the extent that such amount does not exceed the aggregate amount which would have been so includible if all amounts from all individual retirement plans were distributed. Proper adjustments shall be made in applying section 72 to other distributions in such taxable year and subsequent taxable years. . (7) Subparagraph (B) of section 848(e)(1) of such Code is amended— (A) in clause (iv), by striking and at the end