Hi Frank,

Yes that is the study I was referring to. Thank you for providing a much more efficient way to access this information which may be enlightening & helpful to other members.

John

I went back a page on this topic. On 06/09/17 a member (L78steve) posted a link that appears to have the same information as the page Goodsign directed us to. All of this information appears to be over ten years old though. Maybe some of the previous posters will have some new information to bring this discussion up to date.