Monthly supply also rose for the fourth consecutive month, up by 0.6% compared with July, IMnI said in its monthly report for September.
The largest year-on-year increase was seen in the Asia-Oceania region, where the vast bulk of supply is produced.
Supply volume from that region rose by 24% year-on-year to 1.37 million tonnes. This was, however, flat against July this year.
Over the first eight months of 2019, world supply rose by 17.4%, while supply from Asia and...