I am sure that this is a pretty simple one for those that know how, but I am really struggling.

I need to maintain a running percentage for the year where each quarters completed totals are entered. The columns that I have set up are:

A1-Years Target, B1-Q1 Actual, C1-Q2 Actual, D1-Q3 Actual, E1-Q4 Actual Completion, F1-Completion %

Really appreciate any help,
Thanks in advance