As used in this chapter, "trusteed surplus" means the aggregate value of a United States branch's:
plus investment income accrued on the items described in subdivisions (1) and (2) if the investment income is collected by the state for the trustees, less the aggregate net amount of all of the United States branch's reserves and other liabilities in the United States, as determined under section 6 of this chapter.
IC 27-1-40-1