I would be interested to hear what the Westover Heights people said.
The quoted transmission rates are *very* confusing. We are told 10%, but the studies, as you say, are over the course of a year (I have seen two studies that also cite a separate figure, the chance of transmission per 10,000 acts).
If it is 10% divided by, say, 100 sexual acts then that is very low (and even lower with the use of condoms and anti-virals) - 0.1%.
However, a recent study I saw based on mathematical modelling (by some of the same Univ of Washington researchers) used a transmission rate of around 1% per sexual act, so that doesn't make sense either.
As I keep finding when carrying out my own research into the virus, there is so much false and unsubstantiated information out there. Even the 'experts' disagree on a lot of fairly fundamental issues.
I find it amazing that in all studies no-one can actually tell us what the approximate chances of transmitting the virus are for every time we have sex.