Yeah, that data definitely shows that there is almost zero correlation in spending and results. For a while I've thought that the problems we face with public education lie somewhere other than funding, but I've only recently wondered about proof. Do you have any more of your research drawn up in some sort of report. It's always good to have lots of ammo in debates with peers.
I was looking over your source of data (seeing Alabama's education system in such a good light is not very common) and I noticed something you might want to check out. You are comparing state's only on their SAT scores, which for the most part are taken only on a volunteer basis, mainly to get into college. I'm not sure how you interpreted the "Percent of Graduates taking SAT 1999-2000" column (http://nces.ed.gov/programs/digest/d01/dt137.asp), but it looked to me as it though it meant that, for instance, 9 percent of Alabama's graduating seniors took the test and consequently their average score is based on that 9 percent of Alabama's student body. But if you look at D.C.'s data you'll see that 89 percent of their graduating seniors took the SAT. This is an assumption but I believe it to be true: Alabama's brightest and top nine percent of students took the test, while almost all of the students in D.C. took the test, therefore D.C.'s average is "polluted" with all the morons, and Alabama's average contains mostly the smarter students. I hope I didn't misinterpret the meaning of "Percent of Graduates taking SAT 1999-2000," else I shall look fairly ridiculous.
I agree the last thing public education needs is more money, but I thought I might mention the above to you so that you could build a more airtight statistical argument.