The story of feast and famine at Southern California’s twin port complex continued last month, with the Port of Los Angeles reporting its best May ever and the Port of Long Beach reporting another decline, according to statistics released Thursday.

The number of cargo containers passing through the Los Angeles port in May jumped to 731,353, a 5.5 percent increase over the same month last year and the port’s best month overall in nearly two years.

“We hadn’t seen this kind of number since August 2010,” said L.A. port spokesman Phillip Sanfield. “And that was during a peak season. To see that in May is encouraging, and a bit surprising.”

Imports and exports both rose slightly, while the number of empty containers bound for Asia rose 19 percent – an indication those containers will be needed to ship goods to the United States during the peak pre-holiday season.

But while Los Angeles had a record May – following a record April – Long Beach’s cargo numbers have fallen every month this year. Last month, the Long Beach port handled 497,892 containers, down 7 percent from the same month last year.

Exports dipped only slightly – less than 1 percent – but imports were down by 9 percent and empties by nearly 10 percent. Officials at both ports have said they are not sure why Los Angeles’ numbers are booming while Long Beach’s are shrinking.