(b) “Balance ratio” defined For purposes of this section, the term balance ratio means, with respect to any calendar year in connection with any Trust Fund referred to in subsection (a) of this section, the ratio of
(1) the balance in such Trust Fund as of the beginning of such year, including the taxes transferred under section
401 (a) of this title on the first day of such year and reduced by the outstanding amount of any loan (including interest thereon) theretofore made to such Trust Fund under section
401 (l) or
1395i (j) of this title, to
(2) the total amount which (for amounts which will be paid from the Federal Old-Age and Survivors Insurance Trust Fund and the Federal Disability Insurance Trust Fund, as estimated by the Commissioner, and for amounts which will be paid from the Federal Hospital Insurance Trust and the Federal Supplementary Medical Insurance Trust Fund, as estimated by the Secretary) will be paid from such Trust Fund during such calendar year for all purposes authorized by section
401,
1395i, or
1395t of this title (as applicable), other than payments of interest on, or repayments of, loans under section
401 (l) or
1395i (j) of this title, but excluding any transfer payments between such Trust Fund and any other Trust Fund referred to in subsection (a) of this section and reducing the amount of any transfers to the Railroad Retirement Account by the amount of any transfers into such Trust Fund from that Account.