I want to display on a scatter graph all of the schools in the north of England. Each school has a unique reference number. Each school will have a grade from 1 to 4. This grade is the outcome from their last inspection.
What I need to be able to do is display all of the schools by their unique reference number and have them permanently on display, in grey as background data. I then wish to be able to select any grade between 1 and 4 and have those schools display on top of the greyed out schools, in different colours.
Can anyone tell me how I can make this happen please?