pre_text: Gross Profit and Gross Margin (exclusive of amortization of acquisition-related intangible assets described below) Our gross profit by reportable segment was as follows (dollars in millions): (1) Certain of the amounts may not total due to rounding of individual amounts. (2) Unallocated manufacturing costs are presented as a percentage of total revenue (includes expensing of the fair market value step-up of inventory of $19.6 million during 2019 and $1.0 million during 2018). The decrease in gross profit of $265.1 million, or approximately 12%, was primarily due to the impact of the decrease in sales volume, higher fixed costs due to the expansion in our manufacturing capacity as well as the expensing of $19.6 million excess over book value of inventory, commonly referred to as the fair market value step-up, from the Quantenna acquisition. Gross margin decreased to 35.8% during 2019 compared to 38.1% during 2018. The decrease was due to a competitive pricing environment resulting in a decline in average selling prices, higher demand for lower margin products, increased manufacturing costs due to a higher mix of external manufacturing and decreased demand for our products, as explained in the revenue section.
table: 2019 As a % of Segment Revenue (1) 2018 As a % of Segment Revenue (1)
table: PSG $976.0 35.0 % $ 1,110.1 36.5 %
table: ASG 794.8 40.3 % 878.3 42.4 %
table: ISG 275.4 36.4 % 317.1 41.2 %
table: Gross profit for all segments $ 2,046.2 $ 2,305.5
table: Unallocated manufacturing costs (2) (72.6) (1.3) % (66.8) (1.1) %
table: Total gross profit $ 1,973.6 35.8 % $ 2,238.7 38.1 %
question: Analyse this data from a financial earnings document. What is the change in gross profit from ASG from 2018 to 2019?