The total amount to which the claimant may be entitled is normally computed as follows:

(a) The total amount of the loss, damage, or personal injury suffered for which the United States is liable, less any payment the claimant has received from the following sources:

(1) The military member or civilian employee who caused the incident;

(2) The military member's or civilian employee's insurer; and

(3) Any joint tort-feasor or insurer.

(b) No deduction is generally made for any payment the claimant has received by way of voluntary contributions, such as donations of charitable organizations.