Please answer the given financial question based on the context.
Context: humana inc . notes to consolidated financial statements 2014 ( continued ) amortization expense for other intangible assets was approximately $ 75 million in 2017 , $ 77 million in 2016 , and $ 93 million in 2015 . the following table presents our estimate of amortization expense for each of the five next succeeding fiscal years: .
||( in millions )|
|for the years ending december 31,||
|2018|$ 64|
|2019|54|
|2020|52|
|2021|19|
|2022|16|
.
Question: what was the average amortization expense between 2015 and 2017


Answer: The answer is:81.66667