Bluebulb Projects' The Measure of Things presents:
250 is about four-fifths the number of Manned Flights to Space.
In other words, it's 0.8010 times the count of a Manned Flights to Space, and the count of a Manned Flights to Space is 1.250 times that amount.
(2016 figures) (flights with at least 80km altitude; US, Russia, the Soviet Union, and China) Since the flight of the Vostok 1 in April, 1961, there have been a total of 312 manned spaceflights under the American, Russian, Soviet, and Chinese space programs. Furthermore, the space programs of the US, Russia, the Soviet Union, France, Argentina, and Iran have launched a total 32 monkeys (specifically rhesus, cynomolgus, and squirrel monkeys, macaques, chimpanzees) into space.