Tokyo--Jan. 24--Japan's corporate service price index averaged 96.7 (1995=100) in December, declining 0.3% on year, but remaining unchanged versus a month earlier, the Bank of Japan said. The index for 2000 also declined on year, falling 0.5% to average 96.8, but slowing from a 1.5% drop seen in 1999. The data coincides with the central bank's view in its economic and financial report for January that the corporate service price index continues to show slight declines.