The following table calculates our net operating earnings for the years ended December 31, 2016, 2015 and 2014:
Gross written premiums increased $53.6 million for the year ended December 31, 2016 compared to the same period in 2015 due to strong growth across all of our operating segments. Our P&C operating segment increased $34.9 million driven by new business production from our Auto and Property products of $20.9 million and $13.3 million, respectively. In addition, our Marine and Professional Liability operating segments increased $11.3 million and $7.4 million, respectively, as compared to the same period in 2015, driven by new business production in our Craft, Cargo and Fishing Vessel products, as well as increased renewal premiums in our E&O and D&O divisions despite a difficult rate environment.
For the year ended December 31, 2016 average renewal premium rates decreased 4.1%, due to decreases of 1.6%, 8.0%, and 3.5% in our Marine, P&C and Professional Liability operating segments, respectively. The impact of this has been offset by new business production and the commencement of the PV&T product.
For the year ended December 31, 2015, Other operating expenses increased $10.6 million as compared to the same period in 2014, due to continued investment in new underwriting initiatives in continental Europe including new underwriting teams and additional support staff. Higher temporary employment expenses and professional fees were also incurred due to increased regulatory requirements, offset by favorable foreign exchange rates applied to GBP expenses incurred.
For the year ended December 31, 2014, our GlobalRe reporting segment recorded $2.1 million of net prior AY reserve releases primarily driven by $2.0 million of reserve releases from our Marine product, due to lower than expected loss activity. In addition, $4.0 million of RRPs received reduced our Net losses and LAE ratio, primarily driven by our Marine and P&C products. The prior AY reserve releases were partially offset by reserve prior AY strengthening in our A&H and Agriculture products.
In May 2016, our Company received authorization from the PRA and the FCA for a new U.K. based insurance company, NIIC, which we expect to begin writing business in the first quarter of 2017. NIIC utilizes the financial strength rating from S&P for underwriting purposes, and is rated “A” (Strong - stable outlook) by S&P.
We hold non-sovereign securities where the issuer is located in the Euro Area, an economic and monetary union of certain member states within the European Union that have adopted the Euro as their common currency. As of December 31, 2016, the fair value of such securities was $106.6 million, with an amortized cost of $106.8 million, representing 3.6% of our total fixed maturities and equity portfolio. Of this amount, approximately 26.3% represent securities issued by financial institutions domiciled or operating in the Euro Area. Our largest exposure is in the Netherlands with a total of $39.1 million followed by France with a total of $31.3 million. We have no direct exposure to Greece, Portugal, Italy or Spain within the Euro Area as of December 31, 2016.
The following tables set forth our gross and net losses and LAE reserves, incurred losses and LAE, and payments for our asbestos exposures for the periods indicated:
We recognize deferred tax assets and liabilities, which primarily result from temporary differences between the amounts recorded in our Consolidated Financial Statements and the tax basis of our assets and liabilities. At each balance sheet date, we assess the need to establish a valuation allowance that reduces deferred tax assets when it is more likely than not that all, or some portion, of the deferred tax assets will not be realized. The valuation allowance is based on all available information including projections of future taxable income from each tax-paying component in each tax jurisdiction, principally derived from available tax planning strategies. Projections of future taxable income incorporate several assumptions of future business and operations that are apt to differ from actual experience. We regularly review our deferred tax assets for recoverability, taking into consideration our history of earnings, expectations for future earnings, taxable income in carryback years and the expected timing of the reversals of existing temporary differences. When we believe it is more likely than not that a deferred tax asset will not be realized, we establish a valuation allowance for that deferred tax asset. Our valuation allowance as of December 31, 2016 is $0.7 million.