pre_text: Amortization of Purchased Intangible Assets The following table presents the amortization of purchased intangible assets (in millions): The decrease in amortization of purchased intangible assets was due largely to the purchased intangible assets related to the divestiture of SPVSS business on October 28, 2018, partially offset by amortization from our recent acquisitions.
table: Years Ended July 27, 2019 July 28, 2018 July 29, 2017
table: Amortization of purchased intangible assets:
table: Cost of sales $624 $640 $556
table: Operating expenses
table: Amortization of purchased intangible assets 150 221 259
table: Restructuring and other charges — — 38
table: Total $774 $861 $853
question: Analyse this data from a financial earnings document. What was the change in the Amortization of purchased intangible assets between 2017 and 2018?