Japan’s annual export growth slowed to a crawl in September as slumping sales in China shrank the volume of shipments, raising fears that weak overseas demand may have pushed the economy into recession. Ministry of Finance data showed exports rose just 0.6 percent in the year to September, against a 3.4 percent gain expected by economists in a Reuters poll. A third quarter contraction would put Japan into recession, following the second quarter’s negative GDP result.