According to the CDC’s National Center for Health Statistics, drug overdoses involving fentanyl increased by 113% each year between 2013 and 2016. The drug was involved in nearly 29% of all reported overdose deaths in 2016, a huge jump from just 4% five years earlier. At that point, oxycodone was the most common drug in overdoses, at 13%.

The data also shows a significant increase in drug-induced deaths in that time. In 2011, more than 40,000 people died from an overdose. But five years later, in 2016, more than 63,000 people died from drugs, an average of 174 deaths daily. Nearly half of all overdoses in 2016 were associated with fentanyl.

In 2016, fentanyl overdoses were followed by heroin, cocaine, and then methamphetamine, with heroin representing a quarter of all drug-related deaths that year.

“Fentanyl is so deadly, in the geographic regions where it’s been flooding in, deaths soared like we’ve never seen before,” Dr. Andrew Kolodny, co-founder of Physicians for Responsible Opioid Prescribing told CNN.

Unlawful drugs like fentanyl and heroin were the leading cause of accidental drug overdoses, while prescription drugs like oxycodone and hydrocodone were more common in suicides, according to the study.

The U.S. recorded more than double the premature overdose death rates among the 12 wealthiest nations, Fortune reported earlier this year.