Table:
|  | At December 31, |  |
| --- | --- | --- |
|  | 2019 | 2018 |
| Internally-developed software costs | $345 | $291 |
| Payments made to third-party software developers | 31 | 38 |
| Total software development costs | $376 | $329 |
Paragraphs:
5. Software Development and Intellectual Property Licenses
The following table summarizes the components of our capitalized software development costs (amounts in millions):
As of both December 31, 2019 and December 31, 2018, capitalized intellectual property licenses were not material.
Question:
What was the change in payments made to third-party software developers between 2018 and 2019?
Answer: 31-38 = -7