In London in a year there was 214 reported cases of sexual assault by women that got into a unlicensed cab, and 54 rapes in unlicensed cabs (I did not found stuff about licensed cabs, the location I saw this was specifically talking about the unlicensed ones).
Of course, how much of this is real assaults or fake accusations, is not stated either.
I never heard of a single rape case where taxi driver was involved. Taxi driver, refusing to drive women, will loose the license here in 7 seconds.