On January 17, 2018, the interest rate difference is (i) 1.60% between the 5-year variable open and the 5-year variable closed contracts and (ii) 1.46% between the 1year fixed closed and 1-year fixed open contracts. Both differences are supposed to capture the effect of the pre-payment penalties on the interest rates. One would expect a relatively constant premium for the prepayment penalties on the same day. Explain why the pre-payment premium is not constant on January 17, 2018.