Using Drug Enforcement Administration data, The Washington Post sieved nearly 380 million transactions over six years, from 2006 through 2012, looking for shipments of oxycodone and hydrocodone. More than 76 billion opioid pills crossed the nation in those six years—and just six companies distributed 75 percent of them. Just three companies manufactured 88 percent: SpecGx, a subsidiary of Mallinckrodt; Actavis Pharma; and Par Pharmaceutical, a subsidiary of Endo Pharmaceuticals. By 2012, the number of pills had shot up 51 percent, from 8.4 billion in 2006 to 12.6 billion six years later. (Missouri remains the only state without a statewide prescription drug monitoring program.)

This week, the Post made its database public. There’s nothing underground about this epidemic; the drugs come from the same places you buy your antihistamines and cough drops. Here’s a local digest:

Statewide totals: Almost 1.6 billion pills were distributed in Missouri; just over 1.6 billion in Illinois.

Where they came from: Of those 3.2 billion pills, 1.1 billion were distributed by Walgreen Co. In Missouri, the second- and third-largest distributors were McKesson Corporation and Walmart; in Illinois, the second- and third-largest distributors were McKesson Corporation and CVS.

Who made them? In Missouri, 622 million pills were manufactured by SpecGx LLC, followed by Actavis Pharma; in Illinois, 907 million pills were manufactured by Actavis Pharma, Inc.

County totals, ranked—in descending order—by the highest number of pills per person: