When trips are over and it's time to prepare expense reports, the systems allow travelers to record cash expenses and add any explanations desired.
Critics of the American presence object not only to the risk of American lives but also to the cash expense.
That is before the $160 million cash expense of the Seattle purchase.
Entries were arranged by sector, with cash expenses and gains extrapolated from all the different sectors.
This year's net, the difference between cash receipts and cash expenses, may be in the range of $50 billion to $55 billion.
"This incremental increase in cash expenses likely signals the end of a period of dramatically improving cost structure," it said.
The decline this year is expected to result from farmers' larger cash expenses as they increase plantings, and also because of lower Federal subsidies.
Defenders of the current system also contend that unlike other forms of compensation, options do not result in a cash expense.
The figure is the difference between cash receipts and cash expenses during the calendar year.
Free cash flow is the money left over after companies pay all their cash expenses, including taxes.