pre_text: Stock-based Compensation Expense The income tax benefit related to share-based compensation was $66 million, $158 million and $97 million for 2019, 2018 and 2017, respectively. The income tax benefits related to share-based compensation for the periods presented prior to the second quarter of 2018 were offset by an increase in the U.S. valuation allowance. Stock-based compensation expense of $30 million and $19 million was capitalized and remained in inventory as of August 29, 2019 and August 30, 2018, respectively. As of August 29, 2019, $439 million of total unrecognized compensation costs for unvested awards, before the effect of any future forfeitures, was expected to be recognized through the fourth quarter of 2023, resulting in a weighted-average period of 1.3 years.
table: For the year ended 2019 2018 2017
table: Stock-based compensation expense by caption
table: Cost of goods sold $102 $83 $88
table: Selling, general, and administrative 73 61 75
table: Research and development 68 54 52
table: $243 $198 $215
table: Stock-based compensation expense by type of award
table: Restricted stock awards $178 $140 $144
table: Stock options 33 55 71
table: ESPP 32 3 —
table: $243 $198 $215
question: Analyse this data from a financial earnings document. What is the proportion of income tax benefit related to share-based compensation over the total stock-based compensation expense in 2019?