Same here, maybe even less than 5% on ladders.
Martin,
Window cleaners generally only do FORMAL risk assessments and method statements when we're asked; and sometimes when we're asked for these, we'll also be asked for proof of insurance. Normally, it will only be commercial properties of the larger kind who'll require these.
Domestic properties, or small comercial generally don't.
Then the risk/method paperwork is purely generic; the same one will fit almost any normal situation; we just cut 'n' paste company names. Okay, I admit rope access, cradles, cherry pickers (and probably other platforms) will all have very different risk assessments, but this is pretty much niche work.
But of course we all automatically mentally risk assess any property we clean; and each of our own attitudes to risk differs.
I would suggest a relevant question would be the height that WFP users work to. I only go to 2nd floor (3 storey), about 30 to 35 foot, but I believe you can go to 70 foot. That extra height must mean extra risk.