Multifunction display?

Hi guys, just a quickie, might be me being thick or something but i cannot seem to find a button on my latest fabia to change the display next to my speedo's ect so that i may see what my average mpg is?? apparantly it should be located on the wiper blade stick but there is no button to be found? could it be that my model has not been supplied with such a function? please help cheers!