Ningzhu Industries enters into a three-year interest rate swap with a level notional amount of 400,000. The settlement periods are one year. The variable interest rate is the one-year spot rate at the beginning of each settlement period. Ningzhu will swap this variable interest rate for a fixed annual interest rate that is level over the three-year period. You are given the following forward interest rates: Calculate the swap rate.

period	forward interest rate
f0,1	0.035
f1,2	0.045
f2,3	0.06
f3,4	0.07