New Delhi, Aug 17: After plunging for four straightweeks, the annual rate of inflation based on Wholesale Price Index (WPI) went up marginally to stand at 4.05 per cent during the week ended August two.The inflation, which fell by 1.89 percentage points since June 28, rose by 0.03 percentage points during the reference week from 4.02 per cent to 4.05 per cent. Compared to this, annual inflation was 5.98 per cent inthe corresponding week last year. Meanwhile, the official WPI for `all commodities' (base 1981-82=100) rose marginally by 0.1 per cent.