Table:
|  |  | Pension |  |
| --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 |
| Net periodic benefit cost: |  |  |  |
| Expected long-term return on plan assets(1) | 3.6% | 3.8% | 3.3% |
| Rate of compensation increase | 4.4% | 3.3% | 2.7% |
| Discount rate | 2.2% | 2.1% | 1.9% |
| Projected benefit obligation: |  |  |  |
| Expected long-term return on plan assets | 2.0% | 3.6% | 4.0% |
| Rate of compensation increase | 4.3% | 4.4% | 4.4% |
| Discount rate(2) | 1.7% | 2.2% | 2.3% |
Paragraphs:
Assumptions
Weighted-average actuarial assumptions used to determine net periodic benefit cost and projected benefit obligation for the plans for the fiscal years 2019, 2018 and 2017 were as follows:
(1) The expected return on plan assets assumption used in calculating net periodic benefit cost is based on historical return experience and estimates of future long-term performance with consideration to the expected investment mix of the plan.
(2) The discount rate is used to state expected cash flows relating to future benefits at a present value on the measurement date. This rate represents the market rate for high-quality fixed income investments whose timing would match the cash outflow of retirement benefits. Other assumptions include demographic factors such as retirement, mortality and turnover.
Question:
What was the percentage change in the projected benefit obligation discount rate between 2018 and 2019?