Custom Review Fields Range.

So im trying to create a Custom Review Field. What im trying to achieve is ask the reviewr (user doing the review) for a average. I want to give them choices. For example im asking for average class size.

0-50 Students
50-100 Students
100-150 Students
and so on....

I have tried to do this but could not achieve it. Is this possible in anyway? Im doing a drop down selection but its not allowing me to make the choice field 0-50, 50-100.

Is there anyway I can do this? Or if you have a better idea of how i can ask for a average that would be great.

Also when asking for a price average for lets say a restaurant this would be very helpful. Example $20-30 per meal, $30-40 ect...

 

Genius, who am I to think a coder like Bob would miss something like this =D

Thanks guys!!