From the 1920s onwards there was to be a gradual erosion of the church's primacy in education in Zambia. Understanding the need for increased professionalism among its staff the Anglican Church "closed all its schools for 18 months between 1918 and 1920 and brought all their teachers to Msoro for retraining." The Advisory Board devised the Native School Code by 1927 establishing the state as the arbiter of educational standards in Zambia. The state now had the power to deregister schools that did not operate for the prescribed number of days in a year or did not cover adequately the curriculum developed by the Board. The number of registered mission schools declined significantly during this period. "Of the 547 schools run by the White Fathers only 17 qualified as schools under the new conditions." Part of the reason that the Copperbelt Schools were inter-denominational was the pressure from the Board not to allow contending schools to open up in the towns and repeat the rivalry that was prevalent elsewhere leading to small villages with two schools run by competing missions.