Lester company received a seven-year zero interest bearing note on February 22nd 2014 in exchange for property and sold it to porter company,there was no established Exchange price for the property and the note has no ready Market, the prevailing rate of interest for a note of this type was 7% on February 22nd 2014 7.5% of December 1st 2014 7.7% on December 22nd 2015 and 8% on December 31st 2015, what interest rate should be used to calculate the interest revenue from this transaction for the year ended December 31st 2014 and 2015 respectively?