Order Bar Chart in chronological order

I’m trying to set up a chart that will show billable time for each week of the year. Where I have a problem is that each week is placed in order as tasks, and the chart widget places them in alphabetical order, instead of in the order I manually prepared. I tried writing the “Week #” first to force this, but W1 is followed by W10 instead of W2.

I think that more options should be available in the “sort by” dropdown. Board order, would help me here.