Other expense margins have improved in each of the years considered. These improvements have had the effect of further improving margins.
Energy operations: The energy operations of Torchmark include the management ------------------ of proven producing oil and gas properties for both affiliates and unrelated parties by its subsidiary Torch Energy. Energy operations also include drilling of developmental wells, acquisition of properties and facilities, and marketing of oil and gas products by Torch Energy. Additionally, Torchmark and its insurance subsidiaries have invested in energy properties. While these investments are not included in the above table, they are discussed in this report under the caption "Investment Operations."
by the following table, 30% of the fixed income portfolio should repay within five years, and almost 75% within ten years. This compares with 46% and almost 90%, respectively, for year-end 1993. The table presents maturities determined by schedule or by estimated repayment in the case of mortgaged-backed securities.
Liquidity of the parent company is affected by the ability of the subsidiaries to pay dividends. Dividends are paid by subsidiaries to the parent in order to meet its dividend payments on common and preferred stock, interest and principal repayment requirements on parent-company debt, and operating expenses of the parent company. Dividends from insurance subsidiaries of Torchmark are limited to the greater of statutory net gain from operations on an annual noncumulative basis or 10% of surplus, not to exceed earned surplus, in the absence of special approval, and distributions are not permitted in excess of statutory net worth. Subsidiaries are also subject to certain minimum capital requirements. Although these restrictions exist, dividend availability from subsidiaries has been and is expected to be more than adequate for parent-company operations. At December 31, 1994, a maximum amount of $213 million was available to Torchmark from insurance subsidiaries without regulatory approval.
Gains and losses realized on the disposition of investments are recognized as revenues and are determined on a specific identification basis. Unrealized gains and losses on equity securities and fixed maturities available for sale, net of deferred income taxes, are reflected directly in shareholders' equity.
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (continued) (DOLLAR AMOUNTS IN THOUSANDS EXCEPT PER SHARE DATA) NOTE 3--INVESTMENT OPERATIONS (CONTINUED) A summary of fixed maturities available for sale and equity securities by amortized cost and estimated market value at December 31, 1994 and 1993 is as follows:
Depreciation expense on property used in the business was $9.9 million, $9.6 million, and $10.4 million in each of the years 1994, 1993 and 1992. Depletion of energy properties was $11.7 million, $22.4 million, and $19.6 million in 1994, 1993 and 1992, respectively.
Torchmark adopted SFAS No. 106, "Employers' Accounting for Postretirement Benefits Other Than Pensions," effective January 1, 1993. This statement requires that the expected cost of providing future benefits to employees be accrued during the employees' service period until each employee reaches full eligibility. Torchmark elected to recognize the effect of the adoption of this standard immediately as a change in accounting principle as permitted by SFAS 106. The cumulative effect of this change in accounting resulted in a $7.7 million after-tax charge to net income in 1993. It was reported as part of the cumulative effect of changes in accounting principles. In accordance with the provisions of SFAS 106, prior years' financial statements were not restated to apply the provisions of this statement.
Restrictions on cash: A portion of the cash held in financial service -------------------- subsidiaries that function as broker-dealers has been segregated for the benefit of customers in compliance with security regulations. This amount was $13.1 million at December 31, 1994 and $18.2 million at December 31, 1993.