Seems odd that most stations between Paddington & Slough recorded quite a big decrease. Where have all the passengers gone? Did the daily ticket inspections at these stations for several months frighten fare dodgers away?
Ah, having re-read some of the earlier posts I think this can possibly be explained.
The figures are ticket sales
Oyster▸ pay as you was introduced during the 09/10 period wasn't it?
FGW▸ don't sell tickets on oyster so the reduced ticket sales at these FGW stations are probably the result of passengers topping up their ticket at their local corner shop.
Incidentally having moved away, my nearest FGW station is now Dorking Deepdene which isn't in the list above. Neither is Paddington unless I missed it.