We have not amended our previously filed Annual Reports on Form 10-K or Quarterly Reports on Form 10-Q for the periods affected by the Restatement. The financial information that has been previously filed or otherwise reported for these periods is superseded by the information in this report, and the financial statements and related financial information contained in such previously filed reports should no longer be relied upon. We intend to amend our Forms 10-Q for the quarterly periods ended March 31, June 30, September 30, 2015 and 2016 to reflect the restatement adjustments applicable to the periods presented therein.
Other. Other expenses increased $90.8 million, or 19.2%, to $564.1 million for the year ended December 31, 2016 from $473.3 million for the year ended December 31, 2015. The increase resulted primarily from the acquisitions of First Nationwide in 2016 and Warranty Solutions in September 2015, and higher overall costs related to year-end auditing and consulting resources.
Net Realized Gains (Losses) on Investments. We had net realized gains on investments of $8.1 million and $16.4 million for the years ended December 31, 2015 and 2014, respectively. The decrease related to higher other-than-temporary impairment of fixed maturity securities, which were $19.2 million and $8.0 million for the years ended December 31, 2015 and 2014, respectively.
Acquisition Gain on Purchase. We recognized a gain on acquisition of approximately $5.8 million related to the purchase of CorePointe during 2015. We did not recognize any gains on acquisition during 2014.
Equity in Earnings of Unconsolidated Subsidiaries - Related Parties. Equity in earnings of unconsolidated subsidiaries - related party decreased by $3.0 million for the year ended December 31, 2015 to $25.4 million compared to $28.4 million for the year ended December 31, 2014. We had equity income from NGHC of $9.6 million and $14.7 million in 2015 and 2014, respectively, related to decreases in our ownership percentages of NGHC as a result of public offerings by NGHC in 2015 and 2014. This year over year decrease was partially offset by an increase in earnings from our proportionate share of equity income from NGHC's results of operations in 2015 compared to 2014.
Net Earned Premium. Net earned premium increased $150.7 million, or 22.2%, to $829.3 million for the year ended December 31, 2015 from $678.6 million for the year ended December 31, 2014. As premiums written are earned ratably over an annual period, the increase in net premium earned resulted from higher net written premium for 2015 compared to 2014.
the financial condition and near-term prospects of the issuer of the security, including any specific events that may affect its operations or earnings, and for equity securities, forecasted recovery in a reasonable period of time;
Our investment in marketable equity securities classified as available-for-sale consist of investments in preferred and common stock across a wide range of sectors. We evaluated the near-term prospects for recovery of fair value in relation to the severity and duration of the impairment and have determined in each case that the probability of recovery is reasonable and we have the ability and intent to hold these investments until a recovery of fair value. We believe the gross unrealized losses of $2.4 million as of December 31, 2016 are not material to our financial position.
For further information on our investments and related performance, see Note 4. “Investments” in the audited consolidated financial statements included elsewhere in this report.
We have outstanding $150 million aggregate principal amount of our 7.25% subordinated notes due 2055 (the "7.25% 2055 Notes"), with a carrying value of approximately $145 million that bear interest at a rate equal to 7.25% per year, payable quarterly in arrears on March 15, June 15, September 15 and December 15 of each year, commencing on September 15, 2015. The 7.25% 2055 Notes mature on June 15, 2055. We have the right to redeem the 7.25% 2055 Notes, in whole or in part, on June 18, 2020, or on any interest payment date thereafter, at a redemption price equal to 100% of the principal amount of the notes plus accrued and unpaid interest to, but not including, the date of redemption. The 7.25% 2055 Notes are our subordinated unsecured obligations and are structurally subordinated to all our existing and future indebtedness, liabilities and other obligations of our subsidiaries. Interest expense, including amortization of deferred origination costs, recognized on the 7.25% 2055 Notes was $11.0 million and $5.9 million for the years ended December 31, 2016 and 2015, respectively. For further information on the 7.25% 2055 Notes, see Note 15. "Debt" in the audited consolidated financial statements included elsewhere in this report.
We may purchase reinsurance on a proportional basis to cover loss frequency, individual risk severity and catastrophe exposure. We may also purchase reinsurance on an excess of loss basis to cover individual risk severity and catastrophe exposure. Additionally, we may obtain facultative reinsurance protection on a single risk. The type and amount of reinsurance we purchase varies year to year based on our risk assessment, our desired retention levels based on profitability and other considerations, along with the market availability of quality reinsurance at prices we consider acceptable. Our reinsurance programs renew throughout the year, and the price changes in recent years have not been material to our net underwriting results. Our reinsurance generally does not cover war or nuclear, biological, chemical or radiological terrorism risks.