Done. Now you can set a custom start date for the chart.
Also, I have added a speed line that shows your average completion speed in levels per month. The maximum value is around 4.5 (1 level per week) but the right-side axis goes up to 6 for graphical reasons.
This is yet another tool to show you if and when you’ve been slacking off… 
I have only access to my own account, so if you spot any issues on yours, especially if you have “gaps” or other weird features, please post a screenshot.
