Deferred acquisition costs. Deferred acquisition costs include commissions, premium taxes, payments to affinity partners, and other direct sales costs that are directly related to the successful acquisition of insurance policies. These costs, net of ceding allowances, are deferred and amortized to the extent recoverable, over the policy period in which the related premiums are earned. Anticipated investment income is considered in determining the recoverability of these costs. We believe that these costs are recoverable.
General and administrative expenses. General and administrative expenses are composed of all other operating expenses, including various departmental salaries and benefits expenses for employees that are involved in the maintenance of policies, information systems, and accounting for insurance transactions, and other insurance expenses such as federal excise tax, postage, telephones and internet access charges, as well as legal and auditing fees and board and bureau charges. In addition, general and administrative expenses include those charges that are related to the amortization of tangible and intangible assets and non-insurance activities in which we engage.
Net premium written. Net premium written increased by $396.9 million, or 10.4%, from $3,827.7 million for the year ended December 31, 2018 to $4,224.6 million for the year ended December 31, 2019. Net premium written for the P&C segment increased by $362.8 million for the year ended December 31, 2019 compared to the same period in 2018, primarily as a result of decreased ceded premium to the Quota Shares ($232.0 million) upon commencement of the reduced Auto Quota Share Agreement cession in 2019, the acquisition of Farmers Union Insurance ($71.8 million) and decreased ceded premium by the Reciprocal Exchanges ($50.9 million). Net premium written for the A&H segment increased by $34.1 million for the year ended December 31, 2019 compared to the same period in 2018, primarily as a result of growth in our small group self-funded and individual products ($66.0 million), partially offset by the fourth quarter sale of our international business.
Provision for income taxes. Income tax expense increased by $23.5 million, from $53.5 million for the year ended December 31, 2018, reflecting an effective tax rate of 24.2%, to $77.0 million for the year ended December 31, 2019, reflecting an effective tax rate of 19.0%.
Our P&C segment net loss ratio, which includes the Reciprocal Exchanges, decreased from 75.1% for the year ended December 31, 2018 to 73.6% for the year ended December 31, 2019. Excluding the Reciprocal Exchanges, the net loss ratio was 72.9% and 74.4% for the years ended December 31, 2019 and 2018, respectively. The Reciprocal Exchanges’ net loss ratio was 84.2% and 87.1% for the years ended December 31, 2019 and 2018, respectively.
We may generate liquidity through the issuance of debt or equity securities or financing through borrowings under credit facilities, or a combination thereof. We also have a $340.0 million credit agreement, under which there was $140.0 million outstanding as of December 31, 2019. The proceeds of borrowings under the credit agreement may be used for working capital, acquisitions and general corporate purposes.
Net cash provided by operating activities decreased by $76.5 million, primarily due to higher claim payments and settlement of reinsurance balances in 2019.