China’s factory activity was flat in May, according to an official survey released Sunday, raising questions about how much further the country’s economy can shield itself from the fallout of the ongoing Iran war and pressure on demand.

The official manufacturing purchasing managers index moderated to 50 from 50.3 in April, according to the National Bureau of Statistics. Measured on a scale between 0 and 100, a PMI reading above 50 indicates expansion, while a reading below 50 reflects contraction.

The new orders sub-index dropped to 49.9 from 50.6 in April, while the sub-index on production edged down to 51.2 from April’s 51.5. The sub-index for raw material stockpiles fell to 48.6 from 49.3 in April.

China has been less affected by the global energy shock from the Iran war than many other countries, which face inflationary pressures as as oil prices have surged due to the closure of the Strait of Hormuz, through which a fifth of the world’s oil is shipped in peacetime.

Analysts say China’s ample oil reserves and diversified sources of energy have helped the world’s second-largest economy weather the war nearly unscathed.