The profits and losses, income, deductions, and credits, and items of income, deduction, and credits of the limited liability company shall be allocated among the members in the manner provided in the operating agreement. If the operating agreement does not so provide, profits and losses, income, deductions, and credits, and items of income, deductions, and credits shall be allocated on the basis of the pro rata value of the contributions made by each member to the extent they have been made and not returned.