Welcome to the Forum.

In general, you will have to manipulate your data to produce a summary table, which you can then use as the source for your graph(s). However, I can't be more specific than that as you have not given many details about how your data is laid out - it would help if you attached a sample Excel workbook.

To do this, click on Go Advanced (below the Edit Window) while you are composing a reply, then scroll down to and click on Manage Attachments and the Upload window will open. Click on Browse and navigate to (and double-click) the file icon that you want to attach, then click on Upload and then on Close this Window to return to the Edit window. When you have finished composing your post, click on Submit Post.
Please note that the Paperclip icon does not work.

Hope this helps.

Pete