Counting multiple values in single cells

Hi All,

I am new to this forum and not that keep in Excel :-( So forgive me if I'm not using the correct syntax...

I have a sheet containing results of an online survey.
Several columns contain identical data that needs to be "manipulated".

Let's take one column: in a single cell you can have:
- empty
- single text like 3mm
- multi text comma separated like 3mm, 5mm, 7mm, 9mm, ...<increments of 2mm> ... ,35mm
There are 120 rows FYI.

Per column I need to calculate the total amount of each occurance of 3mm, 5mm, 7mm, ... , 35mm

No clue how to tackle this. Working on Excel 2011 for Mac.

All help and tips are really appreciated.

Thanks!