Add total percent from each calculated column.

[janvita]

Hi,

I would like to calculate each cell (from B to F by dividing it with 1600) and get the final average percent (below) in the Total column. Also, I don't want any calculation if a column is blank and would auto calculate once data is present. Any suggestion is greatly appreciated. Thanks!

So in this case: 

Jess:
B1 = 0.75
C1 = 0.46
G1 = (B1 + C1)/2

Phil:
B2 = 0.76
C2 = 0.64
G2 = (B2 + C2)/2


A          B            C           D          E         F        G(Total)
Jess     1200         750                                         60.5%
Phil     1230        1022                                         70%