pre_text: 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.
table: Pension
table: 2019 2018 2017
table: Net periodic benefit cost:
table: Expected long-term return on plan assets(1) 3.6% 3.8% 3.3%
table: Rate of compensation increase 4.4% 3.3% 2.7%
table: Discount rate 2.2% 2.1% 1.9%
table: Projected benefit obligation:
table: Expected long-term return on plan assets 2.0% 3.6% 4.0%
table: Rate of compensation increase 4.3% 4.4% 4.4%
table: Discount rate(2) 1.7% 2.2% 2.3%
question: Analyse this data from a financial earnings document. What was the percentage change in the net periodic benefit cost rate of compensation increase between 2017 and 2018?