Of course, there's always home schooling and non-public education, both small but growing sectors of the school-choice spectrum; both typically produce students far more literate and numerate than their public school peers. (This fact is strongly demonstrated by SAT tests and in-college results.)
The NAEP tests have been around since 1969 with their typically dismal student test-score findings published every year in the National Digest of Educational Statistics. The scores, in such subjects as mathematics and reading, have typically been in the mid-200s.
For example, if you look at table 112 in the 2007 NDES (it covers the years 1971 to 2004) showing 4th graders in reading, they went from 208 to 219 (out of a possible 500), while 8th graders went from 255 to 259; and 11th graders went from 285 to-drumroll-285! These numbers equate to proficiency percentages in the low-20s to high 40s range; for example, Vermont 8th grade students came in at 42 percent proficient (that is, able to function at grade level) in 2007.
No one in education cared much about these percentages as long as the test scores were deep-sixed and went unpublished to the taxpaying public, but that changed with a key part of NCLB that required: 1.) that public schools get almost all of their students to "proficient" by 2014, and 2.) from 2002 on each school must demonstrate measurable Annual Yearly Progress, as measured by improvements in NAEP test score results, towards that goal. (As an aside: to this day, the Vermont NAEP scores still aren't posted on the public education website-wonder why?)
The lawsuit mentioned above also takes a curious direction: it argues that nowhere in a contemporary educator's job-description is the actual requirement (or expectation) that he/she get a specific number or percentage of his/her students to "proficient" and that, therefore, the new and offensive NCLB requirement is really an unfunded mandate as prohibited by P.L. 104-4. In contrast to military education-if the student didn't learn, it's because the teacher didn't teach-or private education with various modes of student evaluation of instructors, public educators are adamant in rejecting student achievement as an indicator of teacher competence.