A search processing unit of a central server searches for radiographing information matched with a designated radiographing part, among all items of the radiographing information of a medical facility having radiographing information matched with a detection device ID from a storage device. A sorting unit performs classification into medical facilities (first group), in which the radiation dose after an X-ray image detection device of the designated detection device ID is introduced has changed from that before the introduction, and medical facilities (second group) in which the radiation dose after the X-ray image detection device of the designated detection device ID is introduced has not changed. A statistical data generation unit generates a histogram, in which the range of radiation dose is set as the class on the horizontal axis and the number of medical facilities is set as the frequency on the vertical, for each of first and second groups.
