Hard for me without a workbook. I still struggle with Table Calculations all the time so I may not be the best person to answer! ... but
1. try adding a reference line
2. try adding a mark label (min/max only)
3. try table calculations again and check out the TOTAL calcuation
4. duplicate the first chart with a second axis for sum(total volume) and then remove the fine classes and sync axis
Thanks Jason,#4 ended up working well for me. I appreciate it!