A hefty increase in China trade contributed to an overall 3.6% growth in traffic through the Los Angeles customs district in 1996, according to the quarterly CMC-Tradeweek Regional Trade Report. Trade with China for that period was up 16.5%. Los Angeles, which handled $170.1 billion in cargo, remained the busiest customs district in the nation, ahead of New York, Detroit and San Francisco. Los Angeles' top five trading partners were Japan, China, Taiwan, Korea and Singapore. Leading exports included computer circuits and parts, aircraft, cotton, cars and auto parts.