Australia's benchmark share index suffered its biggest percentage drop in 6-1/2 years on Monday, led by a global rout on concerns about a China-led global economic slowdown. The S&P/ASX 200 index tumbled 4.09 percent, or 213.3 points to 5,001.3 at the close of trade, the lowest level since July 2013. This is the steepest percentage drop since January 2009. The benchmark is on track for its worst month since the 2008 global financial crisis, having lost 12.3 percent so far in August. Worries about a slowing Chinese economy flared on Friday after a survey showed a further deterioration in manufacturing activity. Adding to the jitters, the Shanghai stock market was down more than 7.70 percent on Monday. New Zealand's benchmark NZX 50 index fell 2.5 percent or 143.88 points to finish the session at 5,607.31.