Carnival Corp. CEO Arnold Donald devoted the first several minutes of his company’s fourth-quarter earnings call to the achievement of a goal set five years ago.

But it’s the future that really has investors worried, sending shares down more than 9 percent by Thursday afternoon. The world’s largest cruise company said its yields — a measure of how much passengers spend per day — were expected to be flat compared to the prior year in the first quarter of 2019.

For the full fiscal year, yields are forecast to increase just 1 percent, lower than what analysts expected. Yields were up nearly 4 percent this year. Analysts had prepared for a weak first half of 2019, but expected the second part of the year to be more robust; now, it’s not clear whether that will materialize.

“More disconcerting is whether the failure to capture meaningful yield growth is predictive of a lower consumer willingness to spend in the category, something we don’t believe we will have a clear picture on until mid-2019,” Morningstar analyst Jaime Katz wrote in a note to investors. “For now, all measures point to spending remaining healthy for the domestic consumer, which represent around half of Carnival’s sourced customers.”

Revenue increased to $4.4 billion in the quarter that ended Nov. 30, up from $4.2 billion last year. Profit fell from $546 million in the last quarter of 2017 to $494 million this year.

The company hit a target set five years ago: achieving double-digit return on invested capital by 2018.

Bookings for 2019 are “considerably ahead” of where they were at the same time a year ago, but at similar prices.

The issue with 2019 yields lies in large part with Europe, where regional brands such as Costa Cruises and AIDA Cruises that command lower prices than the fleetwide average are adding capacity amid economic and political instability. Even when those lines make money, having more ships in those brands pulls down the average, Donald said.

“I think there’s panic out there at this point because you have seen some — whether it’s tour groups or retail providers — start to call out some weakness in some parts of Europe,” said Stifel analyst Steve Wieczynski.

Donald said that despite challenges in the region, the brands will still grow earnings.

“Europe is doing well,” he said. “They’re absorbing their capacity, they’re working to grow yields in the end and we’ll see where we end up.”

Photo Credit: Costa Classica is shown in Malta in this photo from 2015. Parent company Carnival Corp. worried investors with a lackluster forecast for 2019. Mike McBey / Flickr