Normal Operation Current for ESD Diode
To protect your installation, the ESD diode will be in parallel to the protected circuit. As far as I can tell, the current used by the circuit is not relevant for the choice of your ESD diode.

There will be a bit of leakage current that is the stats in page 3 of the datasheet : "IRM reverse leakage current". Since this is a protection diode, in normal behavior it will not let flow current through itself. If there is a problem and the voltage rise, at this moment the diode will conduct in order to protect the circuit.