since you have no DB source, the report only has one detail section printing.
you can either point this to a source that has a lot of rows and use that in your select statement
or maybe create a lot of detail sections and conditionally show or hide each one based on the value of 12350-12345 and create a formula field for each detaill section.
This would be more tedious as you will need to have one detail section per total range that want a user to enter