North Korea may be facing a harsh sanctions regime, but a cluster of companies in Dandong, China still managed to make $2.9 billion worth of illegal shipments to and from the country in just a three-year span.

Only 150 Dandong companies accounted for nearly 25% of North Korea’s total global trade in 2015 and 2016, serving as the gateway for the DPRK to participate in a global financial system that has largely tried to shut it out, according to the latest Project Sandstone report produced by the Royal United Services Institute (RUSI).

“Wow, that’s f—ing huge,” said