In addition, the Corporation's domestic and international operations have branch and affiliate operations conducted from leased premises in various cities in the United States and foreign countries.
(1) Excludes the cumulative effect of accounting changes. The balance sheet data in the table above reflect the adoption of Statement of Financial Accounting Standards No. 115, "Accounting For Certain Investments in Debt and Equity Securities" in 1994 and the adoption of Statement of Financial Accounting Standards No. 113, "Accounting and Reporting for Reinsurance of Short-Duration and Long-Duration Contracts" in 1993, with reclassifications made for 1992. Adoption of the Standard did not affect results from operations or common stockholders' equity. In 1993, the Corporation adopted the accounting prescribed by the Emerging Issues Task Force for multiple-year, retrospectively rated reinsurance contracts. The cumulative effect from prior years recorded in 1993 increased net income by $14 million or $.17 per share. In 1992, the Corporation adopted Statement of Financial Accounting Standards No. 109, "Accounting for Income Taxes". The cumulative effect from prior years recorded in 1992 increased net income by $61 million or $.71 per share. In 1984, the Corporation adopted the practice of discounting certain workers' compensation claims. The cumulative effect of the change in 1984 was $81 million or $.89 per share.
and 10 percent in short-term investments. The pretax yield on these investments was 7.6 percent in 1994 and 7.8 percent in 1993. The portfolio of each subsidiary is managed by local professional asset managers who are overseen by a local Board of Directors and the Corporation's investment department based in Stamford.
The liability for environmental and latent injury claims and claim expenses is management's best estimate of future claim and claim expense payments and recoveries which are expected to develop over the next thirty years. The Corporation continues to monitor evolving case law and its effect on environmental and latent injury claims. Changing government regulations and legislation, newly identified toxins, newly reported claims, new theories of liability, new contract interpretations and other factors could significantly affect future claim development. While the Corporation has recorded its current best estimate of its liabilities for unpaid claims and claim expenses, it is reasonably possible that these estimated liabilities, net of estimated reinsurance recoveries, may increase in the future and that the increase may be material to the Corporation's results from operations, cash flows and financial position. It is not possible to estimate reliably the amount of additional net loss, or the range of net loss, that is reasonably possible.
Common stockholders' equity at December 31, 1994 was $4,859 million, an increase of 2.1 percent over $4,761 million at December 31, 1993. The change in common stockholders' equity was primarily due to net income of $665 million less the decline in after-tax unrealized appreciation of $230 million, stock repurchases of $207 million and dividends paid of $168 million. Common stockholders' equity at December 31, 1993 increased 12.6 percent over the $4,227 million at year end 1992.
At December 31, 1994, the Corporation had $150 million of senior debt outstanding, which is rated AAA by Standard and Poor's and Aa1 by Moody's. The Corporation issues short-term commercial paper to provide additional financial flexibility for its operations. Commercial paper offered by the Corporation has been rated A1+ by Standard & Poor's and Prime 1 by Moody's. At December 31, 1994, $31 million of short-term commercial paper was outstanding with an average interest rate of 6.0 percent and a weighted average maturity of 29.8 days. In June 1994, the Corporation increased its lines of credit through a number of participating banks, from $500 million to $1 billion, to provide additional support for commercial paper issuance and to increase its financial flexibility. At December 31, 1994, the Corporation had no outstanding loans under this facility.
ANALYSIS OF GROSS UNPAID CLAIMS AND CLAIM EXPENSES DEVELOPMENT (IN MILLIONS)
On July 22, 1993, the Emerging Issues Task Force of the Financial Accounting Standards Board reached a consensus on accounting for multiple-year, retrospectively rated reinsurance contracts. The Corporation adopted the EITF's prescribed method of accounting for such contracts during the third quarter of 1993. Accordingly, the Corporation reported a cumulative-effect adjustment of $14 million, or $.17 per share, principally to recognize an asset for the amounts due from retrocessionaires related to favorable contract experience through January 1, 1993.
Fixed maturities -- Fair values for fixed maturities were generally based on quoted market prices or dealer quotes.
The following is a summary of industry segment activity for 1994, 1993 and 1992.