Japan is often divided into regions, each containing one or more of the country's 47 prefectures at large. Sometimes, they are referred to as "blocs" , or "regional blocs" as opposed to more granular regional divisions. They are not official administrative units, though they have been used by government officials for statistical and other purposes since 1905. They are widely used in, for example, maps, geography textbooks, and weather reports, and many businesses and institutions use their home regions in their names as well, for example Kyushu National Museum, Kinki Nippon Railway, Chūgoku Bank, and Tōhoku University.