Japan’s largest labor union group said its workers secured the highest pay deal in more than three decades, supporting the case for further gradual interest rate hikes from the Bank of Japan.

Some 760 affiliated unions under the trade union federation Rengo have so far secured an average pay gain of 5.46% in ongoing annual wage negotiations, according to its initial tally released on Friday. That’s the highest level since 1991 when compared with past final tally figures, and exceeded last year’s initial reading of 5.28%. The report also showed that base pay gains averaged 3.84%, growing faster than last year’s 3.7%.

The figures will be revised several times through the final tally in the summer to reflect more results, which are typically lower than the initial count.