Thanks for the pointer to your thread. Noise was not theimmediate reason why I started my thread on approach paths, but naturally, every one living in West London is interested in the subject.
I would imagine that the point Paxboy was making (and if he wasn't, I will) is that the chart shows an entire day's worth of arrivals (in red, around 650 of them in total, roughly 50% on each runway), and of those, only a handful join the ILS after Putney (as the aforementioned statistics confirm).