The rates of import tax on six of the last seven items Leo imported were 13%, 16%, 11%, 17%, 12%, and 14%, respectively. If the tax rate on the seventh item was either 17%, 15%, or 14%, for which of the three values does the average (arithmetic mean) tax rate per item for the seven items equal the median tax rate for the seven items?
I. 17%
II. 15%
III. 14%