- Historical number in force from 1-A Table In Force Supplement; future number in force computed by adding awards to number in force at beginning of period, and subtracting number of terminations.
- Historical awards based on SSA administrative records; future quarterly awards interpolated from annual awards (shown earlier).
- Historical termination rates computed as ratio of (a) terminations, to (b) exposure of in force population during the period; future termination rates projected based on historical trend and judgment.
- Historical number of terminations computed as beginning-of-period in force plus awards minus end-of-period in force; future number of terminations computed by applying termination rate to exposure of in force population during the period.
- Historical percentage of benefits withheld computed by dividing number withheld by end-of-period in force; future withheld percentages projected based on historical trend and judgment.
- Historical number of benefits withheld computed as end-of-period in force minus number in current-payment status; future number of benefits withheld computed by applying withheld percentage to end-of-period in force.
- Historical number of benefits in current-payment status from 1-A Table Current-Payment Supplement; future number of benefits in current-payment status computed as end-of-period in force minus number withheld.