assigning column roles to imported data using fusion tables

[Roger Erismann]

Hello,

We have a data portal for our current project.  We use google charts and fusion table queries to display the data. I would like to include intervals in our line charts for water quality. How do we assign a column role, in this case the column role is "interval" to imported data from fusion tables ? Thanks our data portal http://www.plagespropres.ch/

Roger @hammerdirt