Which space agency leads in financial investment for the ISS based on 1985–2015 data?

Answer

NASA (U.S.)

NASA’s financial outlay between 1985 and 2015 was $58.7 Billion, which was nearly five times that of Russia and significantly more than all other partners combined during that period.

Which space agency leads in financial investment for the ISS based on 1985–2015 data?
SpaceISSspace explorationInternational Cooperation