Between 1972 and 1985, a number of additional MRLs were added and some of the existing centers were phased out.
بین سال‌های ۱۹۷۲ و ۱۹۸۵، تعدادی از MRLهای اضافی افزوده شد و تعدادی از مراکز موجود حذف شدند.