Can you please explain your problem. I doubt anyone will be able to help you if you do not explain your problem. If you are familiar with Origin then plotting the data should not be a problem. If your data is TCSPC lifetime then you need to multiply the Channel (X-axis) with timing resolution (s/channel) to get in time unit.
Not sure what you are asking, but you could plot efficiency against the number of hours/days/weeks? Convert your x-axis to the number of hours etc. in Excel with respect to efficiency, and then import into Origin.
I too have a same question regarding the graph plotting. I have channel values. Can anyone please explain it clearly. how to convert channel value to time (ns)?