Bill, one of the problems with evaluating flare is the determination of the shadow exposure which is a factor in determining the flare factor. In general flare for a highlight of 100% reflectance is about 1 to 3%. For a flare factor of 2 (1 stop), where will the value of flare equal the camera exposure without flare? Your target's black isn't dark enough. Here is the breakdown of the statistically average scene for a 125 speed film exposure.

Defining K, part 5d p2.jpg

Shadow exposure 4 1/3 stops below metered exposure point is 0.6% reflectance. Your 3.6% is over two stops lighter. In this example, flare equals 0.0034 mcs. Added to the shadow exposure of 0.0034 and you've double the shadow exposure, but add it to the exposure of 0.0169 mcs at 3.2% reflectance and you get 0.0203 which is only a 20% increase.