Cullumber, Inc., has just set up a formal line of credit of $$10$ million with First Community Commercial Bank. The line of credit is good for up to five years. The bank will charge Cullumber an interest rate of $6\mathrm{.}15$ percent on any amount borrowed, and the firm will pay an annual fee of $54$ basis points on the unused balance. The firm borrowed $$7\mathrm{.}5$ million on the first day the credit line became available. What is the effective interest rate on this line of credit? $($Round answer to $2$ decimal places, e$.$g$.12\mathrm{.}25\%.)$