Ownership during lifetime.

For the purposes of this section, the term “net contribution” of a party means the sum of all deposits to an account made by or for the party, less all payments from the account made to or for the party which have not been paid to or applied to the use of another party and a proportionate share of any charges deducted from the account, plus a proportionate share of any interest or dividends earned, whether or not included in the current balance. The term “net contribution” includes deposit life insurance proceeds added to the account by reason of death of the party whose net contribution is in question. During the lifetime of all parties, an account belongs to the parties in proportion to the net contribution of each to the sums on deposit, unless there is clear and convincing evidence of a different intent. As between parties either married to or domestic partners of each other, in the absence of proof otherwise, the net contribution of each is presumed to be an equal amount. A beneficiary in an account having a POD designation has no right to sums on deposit during the lifetime of any party. An agent in an account with an agency designation has no beneficial right to sums on deposit.