Headline inflation fell to an over two-year low of 6.55 per cent in January 2012, on the back of cheaper food items. Headline inflation, as measured by the Wholesale Price Index, WPI, had stood at 7.47 per cent in December 2011, and at 9.47 per cent in January 2011.As per the official data released on Tuesday, food inflation stood at minus 0.52 per cent in January 2012, against 0.74 per cent in December 2011. Vegetables were cheaper by 43.13 per cent, and wheat cheaper by 3.48 per cent, on an annual basis.Potato prices fell 23.15 per cent, and onion prices dropped 75.57 per cent, year-on-year, in January. Prices of manufactured items, which have a weight of around 65 per cent in the WPI basket, rose 6.49 per cent in January 2012, as against 7.41 per cent in December 2011.Finance Minister Pranab Mukherjee on Tuesday said that the rate of price rise is still not at acceptable level and hoped for further moderation.Meanwhile, Planning Commission Deputy Chairman Montek Singh Ahluwalia expressed confidence that inflation will moderate further and the government is on right track to contain the price rise.