Thanks for the update. I have been doing some testing and it seems that it likes to only have numerical values here for this axis. Looking in the code for the functions that are creating the xml I'm not sure if you will be able to add in your own label to the yvalue. I have opened a ticket for you on this so we can look into a bit more. To check the status of your ticket or update it please login to WebAssist.com and visit your support history.