but several others, who I saw before I found TER, have retired.

date from 2002-2006, I would say a good 65-70% have retired

I rarely write reviews - only in a couple of cases and probably submitted to other sites.

However, it seems like the average work duration of even the best escorts tends to be only a few years - rarely more than 10.  Over time, they all seem to disappear for various reasons.  Of many ladies I saw back in the 90's, only 2 are still working that I know of.

I suppose if you wait a few years, the answer to your question is probably 100%.

Here in SF Bay Area and Silicon Valley, I'm guessing the average career length of our local providers is probably longer than the average career length of engineers in the high-tech industry (I heard that it's around 14 months).