The ninth annual report on optimal school size for New Mexico's Albuquerque Public Schools presents enrollment and cost figures for the district's elementary, middle, and high schools and for its special education programs. From these data are drawn the minimum school size for economic operation and the maximum school size for effective learning at each educational level. The figures indicate that declining enrollment at the middle and high school levels affected optimal school sizes, while upper and lower limits for elementary schools remained relatively unchanged from those of a year before. Extensive tables relate school size and costs per pupil and relate school size, occupancy rates, and administrative and instructional costs. Additional tables present transportation cost figures and overall summaries. (PGD)