Frankfurt airport, Europe's largest air cargo hub, saw traffic decrease 2.6 percent year-over-year in 2015, mirroring declines at third- and fourth-ranked Amsterdam Schiphol and London Heathrow.

Air cargo handles much of the high-value goods that don't move by ocean vessel in international trade. Its focus on express cargo allows freight companies to depend on reliable delivery and speed to market, although at a premium prices. Many of those shipments are arranged by air freight forwarders who consolidate various goods to make up a shipment lot.

These spectacular jumps in net income and operating profit paint a somewhat unrealistic picture of the year-over-year differences, but even after adjusting for one time charges in both 4Q14 and 4Q15 (see below), it is safe to say that UPS capped a very strong year with an exceptionally strong quarter, and that it expects to continue that strong performance through the coming year.