PROB §5134: (a) “Net contribution” of a party to an account as of any given time is the sum of all of the following: (1) All deposits thereto made by or for the party, less all withdrawals made by or for the part

(a) “Net contribution” of a party to an account as of any given time is the sum of all of the following: (1) All deposits thereto made by or for the party, less all withdrawals made by or for the party that have not been paid to or applied to the use of any other party. (2) A pro rata share of any interest or dividends earned, whether or not included in the current balance. (3) Any proceeds of deposit life insurance added to the account by reason of the death of the party whose net contribution is in question. (b) In the absence of proof otherwise: (1) Only parties who have a present right of withdrawal shall be considered as having a net contribution. (2) The net contribution of each of the parties having a present right of withdrawal is deemed to be an equal amount. (c) It is the intent of the Legislature in enacting this section to provide a definition for the purpose of determining ownership interests in an account as between the parties to the account, and not as between the parties and the financial institution.