President Trump tweeted this week about the synthetic opioid fentanyl, complaining that Chinese suppliers are shipping it to America through the U.S. Postal Service and complaining that the Senate hasn’t passed legislation that would strengthen anti-smuggling measures.

“The Senate should pass the STOP ACT – and firmly STOP this poison from killing our children and destroying our country. No more delay!” he wrote.

It wasn’t clear what prompted Trump to weigh in at that particular moment, but there’s no doubt that illegal fentanyl is a growing problem in the United States with more people using it and dying from it every year. Here’s a look at the data: