Interesting source. A legal practise, right? Not saying they're wrong but iirc over the last few years, admittedly before pandemic, there were more than a few news reports about how the incidence of driving under the influence of drink or drugs has been increasing after the drop caused by changing acceptance levels of it in society.
Of course incidence isn't the same as successful enforcement. A lot of incidents would never get reported or identified.
No expert like most on here but if you're interested in going to the data in such matters I think it's always better going to the source data not secondhand reports of the data. Like I do and others on here it seems.
There's a guy on another forum I visit who's a past master at going to the source data. I think of him as the forum librarian / chief researcher. Never seen him quote a questionable source ever.