Create two different expression, If you using this in Text Box
=NUM( SUM( IF ( Field1 > variable,1,0 ) )/ Count( Distinct Trips ),'##,##')/100
One More Simple text box with only % inside it.
Now put this 2nd text box on the top of 1 so that it will appear after number...
also make sure the second text box should be having TOP layout
This can be done by select TOP from Layout tab.
No, since settings like font and size apply to expression output as a whole.
Your question is sparse on details of the context. IS your expression used in a text box? In a Pivot/Straight table? In a caption?
In a Straight table, you could define a second column with fixed content (just a %) that is left aliigned. Text properties for the '%'-column can then be tuned using the Custom Format Cell-dialog (i.e. text size can be reduced to 80%) You can remove the cell border between the two as well.