The Institute of Physical and Chemical Research or RIKEN is the central laboratory of Japan and collaborates with the Imperial University System. RIKEN is a nonprofit research institute that is supported by the government's Science and Technology Agency. The annual budget is $200 million, of which 90.3% comes from the government. The on-campus staff consists of 1,300 researchers, including 300 scientists and 200 engineers and technicians. The 1,600 visiting scientists include 100 foreign postdoctoral fellows, 100 Japanese postdoctoral fellows, 140 researchers from Japanese companies, and 400 graduate students. Companies pay 30% overhead to support their visiting scientists, and the government pays 10% overhead to support their visiting scientists.