Projections of import cargo volume at the nation’s major retail container ports suggest a 22-month streak in retail sales growth should continue beyond this summer, according to the latest Global Port Tracker report from the National Retail Federation.

Import cargo volume at the nation’s largest container ports is expected to increase 4.8 percent in June compared with the same month last year, and year-over-year increases are expected to continue into the holiday season shipping cycle, according to the report, which was prepared for NRF by Hackett Associates.

“Cargo numbers don’t correlate directly into sales numbers, but they are an indicator of how much retailers think they can sell,” said NRF Vice President for Supply Chain and Customs Policy Jonathan Gold.

U.S. ports followed by Global Port Tracker handled 1.23 million Twenty-foot Equivalent Units in April, the latest month for which after-the-fact numbers are available. That was up 3.9 percent from March and 1.5 percent from April 2011. One TEU is one 20-foot cargo container or its equivalent. The first half of 2012 should total 7.3 million TEU, up 2 percent from the same period last year. The total for 2011 was 14.8 million TEU, up 0.4 percent from 2010’s 14.75 million TEU. NRF projects 2012 retail sales will grow 3.4 percent to $2.53 trillion.

“Consumer demand for durables has been weak for quite some time and dropped further in May, yet at the same time consumer confidence is at its highest level since 2007,” Hackett Associates founder Ben Hackett said. “Confused? So is the average consumer.”