How do you define thickness with a table?

[Snowboarddesign]

I am modeling a tapered laminated solid with SOLID 186. I am inputting the xsec

sect,1,shell
secdata ,1,2,0,5
secdata ,1,2,45,5
secdata ,9,1,0,5
secdata ,1,2,45,5
secdata ,1,2,0,5

I know that when I mesh the model, the layer thickness is automatically scaled to the thickness of the volume, but my aim is to have the outer layers stay at a constant thickness while tapering the middle layer.

Any suggestions on how to do this?

Thanks