OT: Looking at the attainable, mine is very significantly higher than anyone else's. I'm close to the cab, but it isn't in my front garden!
That will likely be because your cab is brand new without many users.
Ive lost 30Mb so far from my max attainable which is purely down to crosstalk. Im not alone, I think its fair to say that an average figure at one year would be 20Mb.
PS
@ jelv - thanks for having some good sense and obscuring the user names - I note users on PN forums do that too.
Not so on another site Ive seen where I saw someone having done a screen shot of that page which could be viewed by anyone and everyone.