Japan\'s benchmark Nikkei 225 Stock Average tumbled just over 2 per cent Wednesday as investors showed disappointment over the central bank\'s latest plan to counter deflation. The Nikkei lost 222.94 points, or 2.08 per cent, to end at 10,486.99 while the broader-based Topix index was down 13.36 points, or 1.48 per cent, at 887.79. On Tuesday, the central bank decided to set a target of 2-per-cent inflation to counter chronic deflation and the strong yen, which hurt the economy. The target was requested by Prime Minister Shinzo Abe, who took office in late December, according to a report of DPA