Superframing and ESF ... A Little Confused

Hi folks, I could really do with some help with something.

I'm studying telecoms in particular T1 circuits. Currently its on about superframing and Extended Superframing.

Ive been reading something:

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D4 Voice and Data Signaling

The transport of signaling states is required in Switched voice or data

(Switched 56K service). Signaling is accomplished through a "Robbed Bit" method where bit 8 of each channel's timeslot is "robbed" to indicate a signaling state in the 6th and 12th frames. Effective throughput for the A signaling bit (Frame 6) is 666.66 BPS. Effective throughput for the B signaling bit (Frame 12) is the same (666.66 BPS).

But i cant figure out how they got to 666.66Bps?

Looking at the diagram on the webpage, the least significant bit in all channels has the last bit robbed, for frames 6 and 12, so in every superframe thats sent, thats 24 bits, multiply that by 8000 and i get

192Kbps???? Where am i going wrong.

Could someone explain this to me.

Thanks in advance.