The government said Friday its key gauge of the current state of the economy stayed above the boom-or-bust line in May for the fourth straight month.

The index of coincident indicators rose to 100 percent from 80 percent in April. It is the first time since November 1996 that the index has hit 100 percent, the Cabinet Office said in a preliminary report.

An index reading of above 50 percent is considered a sign of economic expansion and a figure below that is viewed as a sign of contraction.