To put it into context, Berdych also reached 400 wins this week but is 2 years 8 months older than Andy.
I think it's a one year, eight month difference. He's 27 now, and will be 28 in September. Still very impressive and gives good context. Berdych has had an excellent career by any normal measure. For a little extra context, he's had almost 100 more ATP losses (222 compared with 126), so he's entered a lot more tournaments in his time.