Gary C. Kelly, Chairman of the Board and Chief Executive Officer, stated, “We are delighted to report record annual profits for 2016, our 44th consecutive year of profitability. Our total operating revenues reached a record $20.4 billion, with sustained demand for our legendary low fares and superior Customer Service. Our profit margins were very strong, and our ROIC was a near-record 30.0 percent. Our record profits and balance sheet discipline generated record free cash flow, allowing us to return significant value to our Shareholders. Operationally, our performance was also very solid. We carried a record number of Customers while improving our ontime performance, baggage delivery rate, and net promoter score. My thanks and congratulations to the superb People of Southwest for these outstanding results, which earned them $586 million in profitsharing during 2016.
“We ended the year with a solid fourth quarter 2016 performance. Total operating revenues grew 2.0 percent, year-over-year, to a fourth quarter record $5.1 billion, exceeding our expectations as of the beginning of the fourth quarter. Travel demand and close-in yields improved post-election. In addition, December business travel was stronger than anticipated leading up to the holiday period. Based on current bookings and revenue trends, we estimate first quarter 2017 operating unit revenues will be flat to down one percent, year-over-year. This represents a continued and sequential improvement from the 2.9 percent operating unit revenue year-over-year decline in fourth quarter 2016, which is an encouraging start to the year.
“As expected, our fourth quarter unit costs increased, year-over-year, due to higher fuel costs, pay increases from amended union contracts, and additional depreciation expense associated with the accelerated retirement of our Boeing 737-300 aircraft. While inflationary cost pressures are expected in 2017 due to the union contract pay increases, we are continuing our efforts to drive offsetting cost efficiencies through fleet modernization and ongoing technology investments in our operations.
“During fourth quarter 2016, we began service to Cuba with daily flights to Varadero, Havana, and Santa Clara. We also launched international flights from Los Angeles International Airport (LAX) to Cancun, Puerto Vallarta, and Los Cabos, Mexico. In commencing this LAX service, we were the first U.S. carrier to launch new service between the United States and Mexico under the recently approved Air Transport Agreement. Earlier this month, we filed an application with the U.S.