Hole Wizard Size for DME Ejector Pins

I was trying to add few ejector pin holes in a mold assembly and noticed that the "close" size for a DME THX ejector pin hole is smaller than the pin size.

Please see the attached table from Toolbox

For Eg: For 1" ejector pin, close size is 0.995

Can someone please explain the reason why it should be smaller?

SolidworksToolbox