UCR operated under a $727 million budget in fiscal year 2014–15. The state government provided $214 million, student fees accounted for $224 million and $100 million came from contracts and grants. Private support and other sources accounted for the remaining $189 million. Overall, monies spent at UCR have an economic impact of nearly $1 billion in California. UCR research expenditure in FY 2018 totaled $167.8 million. Total research expenditures at Riverside are significantly concentrated in agricultural science, accounting for 53% of total research expenditures spent by the university in 2002. Top research centers by expenditure, as measured in 2002, include the Agricultural Experiment Station, the Center for Environmental Research and Technology, the Center for Bibliographical Studies, the Air Pollution Research Center, and the Institute of Geophysics and Planetary Physics.