Tokyo, May 23 (BridgeNews) - Japan's April corporate service price index (CSPI) averaged 96.4 (1995=100), a fall of 0.7% on year and 0.1% on month, the Bank of Japan said. The April CSPI indicates Japan remains in a state of deflation. The BOJ said the reason April's 0.7% decline was slightly smaller than the 0.8% drop in March was that prices for software development rose 0.8% in April but had posted no change in March.