... e.g. the most recent average for PER since they encashed your fees, is 27-35 days...
I think it depends on the office to another office. For instance, in VO Vienna, it seems to me that are not so quick as those of New Delhi. Look at the int_tracker and you will see how quickly they working. I hope that I, and everyone else, get PER faster, as now seems to have a little speed up the process.