Spread sheet created linking into to a Pie chart. Excel 2011 on Mac computer

I need the following to be compatible with my Apple Mac and Excel 2011 for Mac

- An 8-9 column spread sheet, so a table will suffice with the info I give you.
- A drop down list (including items: relocation, medical, personal circumstances, etc.) created in the last column on the right of the table.
- Each time an item in the drop down list is selected, I'd like them to be added up and placed into a pie chart. Example: if
relocation was chosen 3 times, medical 6 times, personal circumstances once, then the pie chart would show 30%, 60% and 10% respectively.

I also need a separate tab explaining how you created all this.

PLEASE NOTE: there are NO data entries required there than 8 column headings. The objective is to have functional pie chart that works from the drop down list.

This shouldn't take you long but I need a quick turnaround.

Many thanks,