Drug overdoses in 2016 killed 63,632 Americans, or 174 people a day, a 21 percent spike from 2015, according to new federal data.

Opioids were involved in more than 42,000, or nearly two-thirds, of those deaths.

The spike in overdoses is attributed to the boom of synthetic opioids such as fentanyl, which is 100 times more powerful than morphine and 50 times more potent than heroin, according to the Centers for Disease Control and Prevention.

The analysis released Thursday comes a week after Congress passed a spending bill that included $3.3 billion for fighting the opioid epidemic. Lawmakers have said the funding will likely go towards expanding treatment options.

Fentanyl can be illegally manufactured and shipped easily into the U.S. A congressional probe this year found it was as simple as typing “how to buy fentanyl” into Google.

The analysis found that the death rate from prescription opioids increased by 10.6 percent from 2015 to 2016. The death rate related to heroin overdoses increased by nearly 20 percent.

Death rates differed wildly by states. Overall, 10 states doubled their overdose death rates linked to synthetic opioids.

New Hampshire, West Virginia, and Massachusetts had the highest death rates from synthetic opioids, the CDC said. West Virginia, the District of Columbia, and Ohio had the highest rates for deaths involving heroin.