Calculation of 'Rate' value in MT5 Exposure Tab

 

Does anyone have a clue on how the 'Rate' value in the MT5 Exposure Tab is calculated? I have been trying to find an answer to this for weeks. It is not clearly not a simple inverse of the bid or ask price from the currency listed to the account currency, as you can see from below screenshot (e.g. the rate for CHF does not even come close to the going EURCHF bid or ask prices, or inverse for that matter).

Any help is much appreciated!


 
Well it's not really an "exchange rate", so I guess they could have come up with a better term for it. How it's calculated, that's the easy part: simply divide your current balance by the total volume negotiated (in that specific pair).
 
I'm not quite sure I understand your answer. I have divided the current balance by the above listed volumes and do not see how the 'Rate' value comes from that. Can you give me an example, using the above picture, for any of the listed currencies?