Automatically update a graph each time worksheet is updated

I have a training record for team members that they update periodically and that shows the percentage of training complete. I would like to update my graph automatically to monitor progress every time their training percentage increases without having to save a separately dated sheet each time.

Just keep entering your data (like in cells G1 to K2)
Then click anywhere in the chart itself and your data A1 to F2 should be highlighted in blue and purple.
Move your mouse at the very end of your data and your mouse pointer should change to lines with arrows on both ends
Then simply drag the mouse over into your new data.

The problem I have is that is that the individual team members update their training sheets as they go, that is linked to the supervisors sheet which I attached and although the supervisor can see for example when he looks at his sheet today he will see Team Member A has 10% training complete in the Column marked "overall" when he checks back in a month it may read 50 but I would like to plot the progress on a graph so we can see when the Team members sheet was updated. Apologies if not explaining this very well.