China’s imports from top supplier Russia jumped 58 percent from a year earlier to 7.347 million tonnes, according to the General Administration of Customs data, marking the highest ever and equivalent to about 1.73 million barrels per day (bpd).

For the first 10 months, Russian imports were at 57.91 million tonnes, or 1.39 million bpd, up 16.6 percent.

Chinese customs last month began updating an online database with commodity imports by country of origin, replacing a service that had until March only been available to clients. Percentage changes with year-earlier figures were calculated by Reuters.

China’s crude import demand hit an all-time high in October and is expected to stay strong to year-end as independent refiners snap up cargoes to use up their import quotas.

The strong demand from China’s so-called “teapot” refiners has helped to push spot premiums for popular grades such as Russian ESPO Blend and Oman crude to their highest in more than four years.

Iranian shipments, however, tumbled 64 percent in October from the year-ago month to 1.0496 million tonnes, about 247,160 bpd, ahead of U.S. sanctions that came into effect on Nov. 4.

Month-on-month, imports from Iran in October marked their third fall in a row as China’s state oil firms came under growing pressure to scale back purchases ahead of the sanctions.