Table:
|  | For the Fiscal Years Ended |  |  |  |
| --- | --- | --- | --- | --- |
|  | March 31, 2018 |  | March 31, 2017 |  |
|  | Amount | % to Net Sales | Amount | % to Net Sales |
| Net sales (1) | $201,977 |  | $182,228 |  |
| Segment operating income (loss) (1) | 3,622 | 1.8% | (9,028) | (5.0)% |
Paragraphs:
Film and Electrolytic
The table below sets forth net sales, operating income (loss) and operating income (loss) as a percentage of net sales for our Film and Electrolytic reportable segment for the fiscal years 2018 and 2017 (amounts in thousands, except percentages):
(1) Fiscal years ending March 31, 2018 and 2017 adjusted due to the adoption of ASC 606
Net Sales
Film and Electrolytic net sales of $202.0 million in fiscal year 2018 increased $19.7 million or 10.8% from $182.2 million in fiscal year 2017. The increase in net sales was primarily driven by an increase in net sales in the distributor channel across all the APAC and EMEA regions of $13.7 million, a $3.3 million increase in net sales in the OEM channel of the EMEA region and a $4.2 million increase in the EMS channel across the Americas, EMEA, and APAC regions. These increases were partially offset by a decrease in net sales of $1.2 million in the OEM channel across the Americas, APAC, and JPKO regions. In addition, there was a favorable impact of $7.6 million from foreign currency exchange primarily due to the change in the value of the Euro compared to the U.S. dollar.
Reportable Segment Operating Income (Loss)
Segment operating income of $3.6 million in fiscal year 2018 improved $12.7 million from $9.0 million of operating loss in fiscal year 2017. The improvement was primarily attributable to a $4.3 million increase in gross margin driven by higher net sales, as well as the benefit of completed restructuring activities. The increase was also attributed to an $11.7 million improvement in (gain) loss on the write down and disposal of long-lived assets. These improvements were partially offset by a $2.1 million increase in restructuring charges, a $0.7 million increase in SG&A expenses, and a $0.6 million increase in R&D expenses.
Question:
How much did segment operating income change between 2017 and 2018?