< PrevNext > 28. Citi New York City Share 2017 U.S.-Booked Air Volume: $120 millionConsolidated U.S. TMC: CWTInvestment bank and financial services firm Citigroup in 2017 saw revenue and some travel activity increase from 2016. The company's business air travel last year accounted for about 151,100 metric tons of carbon dioxide equivalent emissions, more than 11 percent higher than in 2016. However, its 2017 rail travel generated 209 metric tons of such emissions, down from 2,225 the prior year. Still, Citi has procedures in place to encourage would-be travelers to consider remote conferencing options instead of traveling, including a prompt within its online booking system. The company also encourages employees to group trips together when possible, to reduce sheer volume of trips and to prioritize rail travel over air when possible.Net revenue in 2017 increased about 2 percent to $71.5 billion. Operating expenses declined less than half a percentage point to $41.2 billion. Citi at the end of 2017 had about 209,000 full-time employees, about 10,000 fewer than at the end of 2016.