Sankey Bar Chart - Columns in Date Order

I have a Sankey Bar Chart but it orders the columns based on the size of the column rather than being in a fixed date order. 

For example, if my data peaks in 2013, the chart can end up in an order such was 2013 2014 2012. Is there any way to fix the positions so they're always 2012 2013 2014 irrespective of the numbers each year has?

Thanks,

Andy