Ranges intervals explanation

Q: Hello, we’ve received a request from a member of staff as to whether the categories of data which are currently set to 0-5, 5-10, 10-15 etc can be changed so that 5 and 10 for example are not repeated in both 0-5, 5-10 and 10-15. The categories would then be 0-5, 6-10… We know how to change the labelling of the categories in Display Query but we can’t find a way to see what the data actually contains and we’re unable to edit the ‘Value’ side of the Ranges tab under ‘Properties’ and ‘Display Query’? Please could you help.

A: Categories of data are intervals left-closed, what can be easily explained by image below:

So according to your question, eg. number 5 is not repeated in both ranges, but it’s only in upper range – 5 to 10. I would suggest to rename your categories of data as following:
0-4, 5-9, 10-14, 15-… etc.
I hope it seems clearer now.