yep, those were peak figures. actually i supplied every value > $21B.
i sort of suspected something like that myself as i was typing them (which is why i went further back than just last year) - those were all "top" months.
i remember coming across a bar chart of inflows for this year somewhere ... i'll just have to remember where that was ...
i haven't calculated from the charts for the first 3 months of the year, but those given in the text for later months are:
Apr 16B May 12B Jun 6-16B (est)
there's also a little tidbit in there of interest on why it may appear that retail investors are now "timing" the market better (as seen by inflows); the claim being that, because of cost cutting, many institutions are/may be using mutual funds of their competitors for exposure to sectors where they don't have representation (small cap, etc.)