Hello, unless I'm mistaken, we can't answer you with this data alone.
We have no loss coef, no outlet tube section, the temperature of the steam, ...
Stupid question, there is no water meter at the entrance? Nothing is lost, everything is transformed...
Kind regards.
Edit: From the temperature of the steam, we can determine the energy needed to raise 1g of water to this temperature and therefore the electrical power consumed. All that remains is to make a cross product, which should give a volume of water, then calculate the total volume according to the operating time and finally relate it to a flow rate.