Table:
|  | As of December 31, |  |
| --- | --- | --- |
|  | 2019 | 2018 |
| Liability component: |  |  |
| Principal | $92,000 | $115,000 |
| Less: debt discount, net of amortization | (12,776) | (20,903) |
| Net carrying amount | $79,224 | $94,097 |
| Equity component (1) | (14,555) | 22,094 |
Paragraphs:
The 2022 Notes consist of the following (in thousands):
(1) Recorded in the consolidated balance sheet within additional paid-in capital, net of $0.8 million transaction costs in equity. December 31, 2019 also includes $36.7 million market premium representing the excess of the total consideration delivered over the fair value of the liability recognized related to the $23.0 million principal balance repurchase of the 2022 Notes.
Question:
What is the change in Principal from December 31, 2019 to December 31, 2018?
Answer: 92000-115000 = -23000