My speed tests have shown the following values for three different file sizes:
50 of 30534 MByte tested.
Write rate: 4.57 MB / s
Read rate: 19.4 MB / s
Tested 200 of 30534 MB.
Write rate: 8.05 MB / s
Read rate: 20.7 MB / s
1024 tested by 30534 MB.
Write rate: 5.33 MB / s
Read rate: 18.4 MB / s
I hope this helps some people, like me, have searched in vain for such data :)