No, you don't.
I'm not arguing about whether or not the levels are dropping (man, you can make a 7 percent drop look damn good when you can pick the vertical scale, can't you? That's parts per trillion, right?).
The substances were made illegal, so it's not that surprising, but I wouldn't mind seeing a timeline a few decades farther back.
What I am saying is that so far, there seems to be no real evidence that it's actually changing the behavior of the atmosphere. I hear about the "lag," so I guess we wait and see. I don't know at what point the cause and effect relationships start to become a bit iffy.