Data coming out back to front

I have a chart where we have 'weeks out' and revenue comparison. I have attached screenshot. As you see the 'weeks out' (30 to 1) comes out the wrong way round with the weeks increase from 1 to 30 instead of 30 to 1 as in the data table. I have tried changing the data table but it still comes out back to front. How can I change this?