I'm seeing a lot of articles putting the rate at 5%. Google is just so much worse than it used to be...

That 5% figure is 3 years old, and one report from 2018 had the figure at 8.7% so it appears to be dropping. Based on the political climate in the US that number is unlikely to my rise anytime soon.

That 5% figure comes from The Guardian, a British newspaper, which I would actually trust more than a domestic source at this point. Based on what I've read about what the Trump administration has done to the EPA, I would imagine any new pollution reports won't be a possibility for a while.