Cumulative Average Percent Move Since Opening?

[designatedrhythm]

I've really hit the wall on this one.

How do I calculate the Cumulative average percent move from 930am each morning and have it labeled at the top of the chart. I know how to do the labels but I can't get the calculation to formulate correctly.

 

[Emanuel5162]

I want to minus the close or high from the open. Then be able to find the average move that it make in a certain period.