The cost of shipping oil with the largest tankers hit a historic record this week. The new record was set after the biggest wave of attacks on shipping since the start of the U.S.-Iran war in Esfand.

Based on Baltic Exchange data, the freight rate for very large tankers for loading from the Gulf of Oman to destinations in China reached around 450 on the global scale, which is equivalent to about $11.50 per barrel. The figure is the highest level since this index began being published in early this year.

According to a Reuters report, the persistence of high shipping costs could add to inflationary pressures and raise the costs for businesses and consumers, who are already facing uncertainty.