Japanese workers are demanding the largest salary hike since 1993 in ongoing pay negotiations, as both central bank and government officials look for signals of sustainable wage growth that could help drive economic progress.

The Japanese Trade Union Confederation, known as Rengo, said Thursday its member unions demanded an average wage increase of 6.09% this year, up from last year’s 5.85%. This is the first time in more than three decades that they are seeking more than 6%.

Unions representing workers from smaller companies demanded a 6.57% raise, compared with 5.97% last year.