computers relative to other inputs, we conclude that as to these two instrumentalities of learning the trial court's findings again better comport with the weight of the evidence, and support its conclusion that the New York City schools are deficient in instrumentalities of learning. In sum, considering all of the inputs, we conclude that the trial court's findings should be reinstated, as indicated, and that the educational inputs in New York City schools are inadequate. There are certainly City schools where the inadequacy is not "gross and glaring" ( Levittown, 57 NY2d at 48). Some of these schools may even be excellent. But tens of thousands of students are placed in overcrowded classrooms, taught by unqualified teachers, and provided with inadequate facilities and equipment. The number of children in these straits is large enough to represent a systemic failure. A showing of good test results and graduation rates among these students -- the "outputs" -- might indicate that they somehow still receive the opportunity for a sound basic education. The showing, however, is otherwise. B. Outputs School Completion. Concerning the first output, school completion, the proof revealed that of those New York City ninth graders who do not transfer to another school system, only 50 percent graduate in four years, and 30 percent do not graduate or receive a general equivalency degree ("GED") by the age of 21, when they cease to be eligible for free public education. This rate of school completion compares unfavorably with both state and national figures, and the trial court considered it symptomatic of "system breakdown" (187 Misc 2d at 63). The Appellate Division concluded that "there was no evidence quantifying how many drop-outs fail to obtain a sound basic education" (295 2 at 15). That conclusion follows from the Appellate Division's premise that a sound basic education is imparted by eighth or ninth grade. A sound basic education, however, means a meaningful high school education. Under that standard, it may, as a practical matter, be presumed that a dropout has not received a sound basic education. In any event the evidence was unrebutted that dropouts typically are not prepared for productive citizenship, as the trial court concluded. [6] The Appellate Division would have required a precise quantitative division between those dropouts who somehow are adequately prepared and those who are not, but such a requirement is nowhere to be found in CFE.