Help - where do I find.... (starting weight)

Hi
I want to work out how many lb's I have lost overall.
I know roughly what I started but I cant remember exactly the stone / pounds that I put into the system.
Where can I find it, as I can only find what I currently am, I know there is a line chart but it starts in between numbers so that has not helped.
I am guessing it will be obvious but I am missing it...
Thanks :-)