We believe, based upon our experience and industry data, that claims incidence for mortgage insurance is generally highest in the third through sixth years after loan origination. As of December 31, 2019, 76% of our IIF relates to business written since January 1, 2017 and was less than three years old. Although the claims experience on new insurance written by us to date has been favorable, we expect incurred losses and claims to increase as a greater amount of this book of insurance reaches its anticipated period of highest claim frequency. The actual default rate and the average reserve per default that we experience as our portfolio matures is difficult to predict and is dependent on the specific characteristics of our current in-force book (including the credit score of the borrower, the loan-to-value ratio of the mortgage, geographic concentrations, etc.), as well as the profile of new business we write in the future. In addition, the default rate and the average reserve per default will be affected by future macroeconomic factors such as housing prices, interest rates and employment.
During the year ended December 31, 2019, the provision for losses and LAE was $33.0 million, comprised of $50.6 million of current year losses partially offset by $17.6 million of favorable prior years' loss development. During the year ended December 31, 2018, the provision for losses and LAE was $11.6 million, comprised of $36.4 million of current year losses partially offset by $24.9 million of favorable prior years' loss development. In both periods, the favorable prior years' loss development was the result of a re-estimation of amounts ultimately to be paid on prior year defaults in the default inventory, including the impact of previously identified defaults that cured. In 2018, the favorable prior years' loss development includes a $9.9 million reduction of loss and LAE reserves associated with hurricane-related defaults that cured.
Compensation and benefits increased primarily due to an increase in stock compensation expense associated with shares granted in 2018 and 2019 and increased overtime associated with our increased NIW. Compensation and benefits includes salaries, wages and bonus, stock compensation expense, benefits and payroll taxes.
As of December 31, 2019, we had substantial liquidity with cash of $71.4 million, short-term investments of $315.4 million and fixed maturity investments of $3.0 billion. We also had $275 million available capacity under the revolving credit component of our Credit Facility, with $225 million of term borrowings outstanding under our Credit Facility. Borrowings under the Credit Facility contractually mature on May 17, 2021. At December 31, 2019, net cash and investments at the holding company were $98.4 million. In addition, Essent Guaranty is a member of the Federal Home Loan Bank of Pittsburgh (the “FHLBank”) and has access to secured borrowing capacity with the FHLBank to provide Essent Guaranty with supplemental liquidity. Essent Guaranty had no outstanding borrowings with the FHLBank at December 31, 2019.
Unearned premium represents the portion of premium written that is applicable to the estimated unexpired risk of insured loans. Rates used to determine the earning of single premium policies are estimates based on an analysis of the expiration of risk.
We have audited the accompanying consolidated balance sheets of Essent Group Ltd. and its subsidiaries (the "Company") as of December 31, 2019 and 2018, and the related consolidated statements of comprehensive income, of changes in stockholders’ equity and of cash flows for each of the three years in the period ended December 31, 2019, including the related notes and financial statement schedules listed in the accompanying index (collectively referred to as the “consolidated financial statements”). We also have audited the Company's internal control over financial reporting as of December 31, 2019, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).
Essent Guaranty has entered into fully collateralized reinsurance agreements ("Radnor Re Transactions") with unaffiliated special purpose insurers domiciled in Bermuda. For the reinsurance coverage periods, Essent Guaranty and its affiliates retain the first layer of the respective aggregate losses, and a Radnor Re special purpose insurer will then provide second layer coverage up to the outstanding reinsurance coverage amount. Essent Guaranty and its affiliates retain losses in excess of the outstanding reinsurance coverage amount. The reinsurance premium due to each Radnor Re special purpose insurer is calculated by multiplying the outstanding reinsurance coverage amount at the beginning of a period by a coupon rate, which is the sum of one-month LIBOR plus a risk margin, and then subtracting actual investment income collected on the assets in the related reinsurance trust during that period. The aggregate excess of loss reinsurance coverage decreases over a ten-year period as the underlying covered mortgages amortize. Essent Guaranty has rights to terminate the Radnor Re Transactions. The Radnor Re entities collateralized the coverage by issuing mortgage insurance-linked notes ("ILNs") in an aggregate amount equal to the initial coverage to unaffiliated investors. The notes have ten-year legal maturities and are non-recourse to any assets of Essent Guaranty or its affiliates. The proceeds of the notes were deposited into reinsurance trusts for the benefit of Essent Guaranty and will be the source of reinsurance claim payments to Essent Guaranty and principal repayments on the ILNs.
For the year ended December 31, 2019, $11.9 million was paid for incurred claims and claim adjustment expenses attributable to insured events of prior years. There has been a $17.6 million favorable prior year development during the year ended December 31, 2019. Reserves remaining as of December 31, 2019 for prior years are $20.0 million as a result of re-estimation of unpaid losses and loss adjustment expenses. For the year ended December 31, 2018, $7.7 million was paid for incurred claims and claim adjustment expenses attributable to insured events of prior years. There was a $24.9 million favorable prior year development during the year ended December 31, 2018. Reserves remaining as of December 31, 2018 for prior years were $14.3 million as a result of re-estimation of unpaid losses and loss adjustment expenses. In both periods, the favorable prior years' loss development was the result of a re-estimation of amounts ultimately to be paid on prior year defaults in the default inventory, including the impact of previously identified defaults that cured. Original estimates are increased or decreased as additional information becomes known regarding individual claims.
When available, we generally use quoted market prices to determine fair value and classify the financial instrument in Level 1. In cases where quoted market prices for similar financial instruments are available, we utilize these inputs for valuation techniques and classify the financial instrument in Level 2. In cases where quoted market prices are not available, fair values are based on estimates using discounted cash flows, present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rates and estimates of future cash flows and we classify the financial instrument in Level 3. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument.
Net income determined in accordance with statutory accounting practices differs from GAAP. In 2019 and 2018, the more significant differences between net income determined under statutory accounting practices and GAAP for Essent Guaranty and Essent PA relate to policy acquisition costs and income taxes. Under statutory accounting practices, policy acquisition costs are expensed as incurred while such costs are capitalized and amortized to expense over the life of the policy under GAAP. As discussed in Note 12, we are eligible for a tax deduction, subject to certain limitations for amounts required by state law or regulation to be set aside in statutory contingency reserves when we purchase T&L Bonds. Under statutory accounting practices, this deduction reduces the tax provision recorded by Essent Guaranty and Essent PA and, as a result, increases statutory net income and surplus as compared to net income and equity determined in accordance with GAAP.