pre_text: Assumptions Weighted average actuarial assumptions used to determine costs for the plans for each period were as follows: The weighted-average expected long-term rate of return for the plan assets is 3.3%. The weighted-average expected longterm rate of return on plan assets is based on the interest rates guaranteed under the insurance contracts, and the expected rate of return appropriate for each category of assets weighted for the distribution within the diversified investment fund. The assumptions used for the plans are based upon customary rates and practices for the location of the plans. Factors such as asset class allocations, long-term rates of return (actual and expected), and results of periodic asset liability modeling studies are considered when constructing the long-term rate of return assumption for our defined benefit pension plans.
table: Fiscal Year Ended January 31,
table: 2019 2018 2017
table: Discount rate 2.5% 2.4% 3.2%
table: Expected long-term rate of return on plan assets 3.3% 3.3% 4.3%
table: Rate of compensation increase 2.3% 2.3% 2.2%
question: Analyse this data from a financial earnings document. What is the average discount rate over the 3 year period from 2017 to 2019?