The vast majority of US companies operating in China remain optimistic about their business prospects in the world's second-largest economy, according to a survey released Monday by the US-China Business Council (USCBC). Overall, 85 percent of the companies polled said they are optimistic or somewhat optimistic, while 14 percent said neutral. Only 1 percent said somewhat pessimistic. Although the percentage of optimistic and somewhat optimistic dropped slightly from last year's report, and the percentage of neutral expanded, the percentage saying somewhat pessimistic also came down. None chose pessimistic this year, compared with 2 percent in the previous survey. The report, USCBC 2014 China Business Environment Survey Results, was USCBC's annual survey of senior executives at its more than 200 member companies. Half of the respondents are China-based; the other half is based in the US. Eighty-five percent of participating companies have been in the Chinese mainland market for more than 10 years, with the majority having more than 20 years' experience. USCBC President John Frisbie said in a statement about the report that the Chinese mainland market continues to deliver important revenue opportunities for American companies, even as GDP growth moderates.