If that number includes Rxed aspirin it neither shocks nor surprises me.
From the article, it includes only Hydro and Oxy.
While I'm aware that a user will normally take multiple pills of it a day, that's still enough for every resident of the state to take a bit over 1 a day, and I doubt that 25-50% of the state are needing daily doses.
Edit: Scrutinizing the article a touch more, it's also over 6 years, so not quite as bad.
Looks like they're largely blaming it on "select" pharmacies that didn't practice good controls, and that, much like what gun grabbers like to do, blaming the drug companies for not realizing that there's no way that a small mom&pop are selling 600 times as many pills as a Rite-Aid next door legally.