pre_text: Interest and Other Income (Loss), Net Interest Income (Expense), Net The following table summarizes interest income and interest expense (in millions): Interest income decreased, driven by a decrease in the average balance of cash and available-for-sale debt investments. The decrease in interest expense was driven by a lower average debt balance, partially offset by the impact of higher effective interest rates.
table: Years Ended 2019 vs. 2018
table: July 27, 2019 July 28, 2018 July 29, 2017 Variance in Dollars
table: Interest income $1,308 $1,508 $1,338 $(200)
table: Interest expense (859) (943) (861) 84
table: Interest income (expense), net $449 $565 $477 $(116)
question: Analyse this data from a financial earnings document. What was the change in Interest expense between 2017 and 2018?