Reuters reports that Iran’s largest crude oil customers in Asia reduced their oil imports from Iran by 15 percent in the past year.

In a report based on the customs and industry statistics of Iran’s customer states, Reuters writes that China, India, Japan and South Korea collectively imported 935,862 barrels per day from Iran in 2013, which translates into 46 billion dollars in oil revenues for Iran compared to pre-sanctions crude exports of 2.2 million bpd.

The six-month deal reached in November between Iran and the world powers to suspend some of the sanctions is reportedly expected to result in a limited recovery, as Iran is allowed to keep exports at the current level with an eye to increasing shipments later.

Experts are doubtful that Iran could quickly restore its exports to previous levels, since buyers would likely engage in higher-volume deals only after a final diplomatic agreement has been reached in the nuclear negotiations.

Reports indicate that only China has moved to make a slight increase in its oil imports from Iran following the Geneva agreement.

Iran and the 5+1 are set to meet again next month to continue the nuclear talks.