No one disputes that the over-rates have dropped to an appalling level, but things aren't quite as bad as you suggest; you've done the sums as if there were 25 full days of Ashes cricket this year whereas, even forgetting the interruptions from weather, three matches finished on the fourth day, and of those Lord's saw only 50 minutes' play on the fourth, and Edgbaston 100 minutes - so call that 20 and a half before deducting all the time lost, which must have come to two or three days more. I could do the sums from Bill Frindall's cards in The Times, but it would take time.

As a quick option, I'll give you over-rates for each hour at Old Trafford, as I scored that one (the totals come in under the total for the complete innings because I didn't work out a figure for incomplete hours):
First England innings, Aussies bowling: 13, 12, 13, 16, 15, 14, 13, 13.
First Australian innings, England bowling: 12.3, 12, 13, 12.3, 14, 13.
Second England innings: 13, 12.4, 14.2, 12.
Second Australian innings: 15, 14, 14, 13, 15, 11.3, 14.

So they very rarely touched the 15 per hour they're supposed to do (that 16 per hour involved Warne and Katich, and the unexpectedly speedy start to Australia's last innings was because Giles and Vaughan bowled when England were desperate to have a go at the batting despite bad light), but they never dropped to the ten you suggest.