Table:
|  | Years Ended December 31, |  |
| --- | --- | --- |
|  | 2019 | 2018 |
| Sales | $  — | $  — |
| Cost of sales | (901) | (88) |
| Total operating expense | 1,022 | 96 |
| Operating income (loss) from discontinued operations | (121) | (8) |
| Other income (expense) | 10,895 | (24) |
| Income (loss) from discontinued operations before income taxes | 10,774 | (32) |
| Provision (benefit) for income taxes | 2,294 | 6 |
| Income (loss) from discontinued operations, net of income taxes | $ 8,480 | $  (38) |
Paragraphs:
Discontinued Operations
In December 2015, we completed the wind down of engineering, manufacturing and sales of our solar inverter product line (the "inverter business"). Accordingly, the results of our inverter business have been reflected as “Income (loss) from discontinued operations, net of income taxes” on our Consolidated Statements of Operations for all periods presented herein.
The effect of our sales of the remaining extended inverter warranties to our customers continues to be reflected in deferred revenue in our Consolidated Balance Sheets. Deferred revenue for extended inverter warranties and the associated costs of warranty service will be reflected in Sales and Cost of goods sold, respectively, from continuing operations in future periods in our Consolidated Statement of Operations, as the deferred revenue is earned and the associated services are rendered. Extended warranties related to the inverter product line are no longer offered.
In May 2019, we divested our grid-tied central solar inverter repair and service operation. In conjunction with the divesture, the initial product warranty for the previously sold grid-tied central solar inverters was transferred to the buyer. Accordingly, a gain of $8.6 million net of tax expense of $2.4 million was recognized in Other income (expense) and Provision (benefit) for income taxes, respectively, in our discontinued operations for the year December 31, 2019. Operating income from discontinued operations for the year ended December 31, 2019 and 2018, also includes the impacts of changes in our estimated product warranty liability, the recovery of accounts receivable and foreign exchange gain or (losses).
Income (loss) from discontinued operations, net of income taxes (in thousands):
Question:
What was the percentage change in total operating expense between 2018 and 2019?
Answer: (1022-96)/96 = 964.58