Section 22. The department shall conduct continuing inquiry into the effectiveness of the treatment methods it employs in seeking the reformation of juvenile and youthful offenders. To this end the department shall obtain from the commissioner of probation all court record information on its wards compiled subsequent to their discharge from the jurisdiction of the department, and with the cooperation of the commissioner of probation tabulate and analyze these data so that they may be used to evaluate the relative merits of methods of treatment. The results of such studies shall be made available to the public in each annual report of the department. The department shall make an annual report to the governor and to the general court containing, in addition to other matters required by law, a statement of the number of persons committed to the department during the preceding fiscal year and of the disposition made of such persons and of all other persons under its supervision during said year. The report shall include such inventories as the institutions under the department's supervision are required by law to make, a statement of the condition and needs of the facilities under its supervision, and of the progress made towards an integrated rehabilitory system capable of giving the most effective individual treatment for rehabilitation. The report shall include such recommendations for legislation as the department may wish to make.