HONGKONG'S container traffic leapt 30 per cent last year, taking it back to the position of busiest container port in the world. Container throughput was 7.97 million 20-foot equivalent units (TEUs) last year, up 29.4 per cent on 6.16 million TEUs in 1991. Although official figures on Singapore's container throughput for last year are not available yet, it is believed that Hongkong has overtaken Singapore as the busiest container port in the world, if only by a small margin. Mr John Sherman, Assistant Director of Marine, said the results showed a startling increase over 1991. The average increase remained steady, at more than 20 per cent, throughout the year, indicating continuing strong growth. ''In particular, the total throughput of loaded TEUs - that is export and/or re-export cargo - shows the same startling growth rate, which is also 28.6 per cent, and clearly reflects sustained local business confidence in the face of continuing world recession,'' he said. Mr Tony Clark, secretary of the Port Development Board (PDB), said the throughput figures reflected Hongkong's growing economy and that of south China in 1992. It also reflected an effective infrastructure system in Hongkong to sustain this tremendous growth. But Mr Clark, who declined to forecast Hongkong port's growth rate for 1993, said the PDB's statisticians would be working out the estimates using the Government's standard 14.7 per cent growth figure used in its planning for terminals and adding the percentage of growth for the stream and river trade. Container throughput at Kwai Chung terminals rose 12.5 per cent to 5.07 million TEUs last year against 4.51 million TEUs in 1991. ''But the biggest increases are from those handled in the stream and from vessels trading between the Pearl River delta ports and Hongkong [river trade], which show increases of 60 per cent and 379.9 per cent, respectively,'' said Mr Sherman. Mid-stream throughput rose from 1.59 million TEUs in 1991 to 2.55 million last year. River trade throughput rose from 74,378 TEUs in 1991 to 356,949 last year.