Consolidate Percentages

Hi,

Is there an Excel formula where I consolidate the %s so I can just have 1 overall number to compare?

E.g A sales were 38% by value; B sales was 45% by value, C sales was 28% by value etc etc...

Below is the data

8 Weeks Prior 4 Weeks Prior Extra Made % Change Over 4 Weeks Prior % Change Over 8 Weeks Prior
A 395 219 14,984 6742.0% 3693.4%
B 596 513 14,132 2654.7% 2271.1%
C 233 226 11,873 5153.3% 4995.5%
D 478 342 7,334 2044.4% 1434.3%
E 82 56 6,822 12082.1% 8219.5%
F 319 174 6,382 3567.5% 1900.5%
G 3 5 6,046 120820.0% 201433.3%
H 169 179 4,652 2498.9% 2652.7%
I 1 3 3,074 102366.7% 307300.0%
J 8 8 2,759 34387.5% 34387.5%
K 10 1 1,553 155150.0% 15425.0%
L 112 123 1,150 834.6% 926.3%
M 69 60 741 1134.2% 973.2%
N 31 15 147 880.0% 374.2%
O 467 208 -199 (142.5%)
TOTAL 2,973 2,132 81,448 3720.2% 2639.6%