Japan's service industry activity index rose 2.2 percent in 2005 from the previous year for the third straight yearly increase, with the index registering its highest score since 1988, the government said Thursday.

The tertiary industry index -- a measure of demand for services -- stood at 106.6 against the base of 100 for 2000, the Ministry of Economy, Trade and Industry said in a preliminary report.

Among 11 industry sectors, the index for all but one area gained ground in the reporting year. Services including leasing and automobile maintenance made the largest contribution to the yearly gain, while cram schools logged a decline.