Table:
|  |  |  | Year Ended May 31, |  |
| --- | --- | --- | --- | --- |
|  |  |  | Percent Change |  |
| (Dollars in millions) | 2019 | Actual | Constant | 2018 |
| Interest income | $1,092 | -9% | -9% | $1,203 |
| Foreign currency losses, net | (111) | 50% | 62% | (74) |
| Noncontrolling interests in income | (152) | 12% | 12% | (135) |
| Other income, net | (14) | -107% | -42% | 191 |
| Total non-operating income, net | $815 | -31% | -31% | $1,185 |
Paragraphs:
Non-Operating Income, net: Non-operating income, net consists primarily of interest income, net foreign currency exchange losses, the noncontrolling interests in the net profits of our majority-owned subsidiaries (primarily Oracle Financial Services Software Limited and Oracle Corporation Japan) and net other income, including net recognized gains and losses related to all of our investments, net unrealized gains and losses related to the small portion of our investment portfolio related to our deferred compensation plan, net unrealized gains and losses related to certain equity securities and non-service net periodic pension income (losses).
On a constant currency basis, our non-operating income, net decreased in fiscal 2019 compared to fiscal 2018 primarily due to decreases in other income, net in fiscal 2019 , which was primarily attributable to realized gains on the sale of certa in marketable securities during fiscal 2018 , and lower interest income in fiscal 2019 primarily due to lower average cash, cash equivalent and marketable securities balances during fiscal 2019 .
Question:
Why did Oracle's interest income in fiscal 2019 decrease?
Answer: lower interest income in fiscal 2019 primarily due to lower average cash, cash equivalent and marketable securities balances during fiscal 2019 .