Checkbox fields are non-exclusive fields that allow users to select multiple options for one field. Read more about field types here.
When it comes to reporting, it can sometimes get a little confusing to report and/or graph checkboxes.
A good work around for reporting on checkboxes is to create section counts for each option. You can read more about section counts here.
Create a new section and add a filter for one option. Repeat this for as many options as you have in the checkbox field.
TIP: Save time by copying the section.
Once you've created/copied sections for each of your options, create a new section and add section counts to a new report section and set them to the sections you just created.
Graphing Your Results
Only proceed if you wish to learn how to graph your results.
After adding all the section counts, make sure to set them to "Value" under Summary. This will allow you to graph the results.
In the graph properties, make sure to set the data source to "Summaries" and add the values (columns) from your report section.