Opioid prescriptions by volume declined by 12% in 2017, the largest single-year change in a quarter of a century, according to a report from the Iqvia Institute for Human Data Science. That number is based on prescriptions by morphine milligram equivalents, a metric that takes into account the strength and dosage of drugs, but the total number of filled opioid prescriptions also dropped by 10.2% per month, according to the report. Prescriptions for high-dose opioids were filled even less frequently, with a 16.1% decline.

Opioid usage has dropped every year since 2011, fueled by stricter regulation around opioid prescription, changes in clinical usage, and greater public awareness about the dangers of opioid abuse, according to the report. The change between 2016 and 2017, however, was especially dramatic, with prescription reductions seen in every state in the country.

Over time, that decline may translate to a drop in overdose deaths, since prescription or illicit opioids were involved in 66% of all lethal overdoses in 2016, according to CDC data. It could also have a ripple effect on other types of substance abuse, since an estimated 80% of new heroin users start with prescription opioids such as OxyContin — a statistic that may have contributed to the decline in prescriptions in the first place.

“We’re at a really critical moment in the country when everybody’s paying attention to this issue,” Iqvia Research Director Michael Kleinrock told the Associated Press. “People really don’t want them if they can avoid them.”

A number of legislative and policy efforts have also been targeted at limiting opioid prescription and use. CVS, for example, began limiting prescriptions to seven days and prioritizing lower-dose drugs, and a number of legal complaints have been leveled against opioid manufacturers, who have been accused of using misleading marketing tactics that may have caused more patients to get hooked on potentially addicting painkillers.