Your Power Rating numbers and manual calculations will not always match your penetration numbers because product penetrations are rounded to the nearest even number.
For example, here are sample penetration numbers without rounding:
VSC - 29
Other - 7.5
Main - 17.4
GAP - 34.2
TW - 1.7
Key - 0.6
SBP - 10
Lea - 5.5
WS - 0.5
A manual calculation and the Power Rating would give you an actual total of 106.4%.
Because product penetrations are rounded to the nearest even number, this same example would give you these numbers:
VSC - 29
Other - 8
Main - 17
GAP - 34
TW - 2
Key - 1
SBP - 10
Lea - 6
WS - 1
...and your total penetration percentage would be 108%.