I saw the charts you pasted. Good info - but I think it is 1998 information (IIRC). While I doubt that the gap between HS and non-HS test scores has changed much, I am aware that the number of HS'ers has increased much beyond 1998's 1.2MM. Unfortunately, no one can truly assess the size of the HS movement in this country since so many actively avoid being counted (self included).
If you want to get a sense, go to your local church and as the senior pastor about HS'ers in the congregation. I'd slap a dollar on the table that says the pastor could name at least one. Scientific? Nope! But it should give the naysayers something to thunk upon...
