pre_text: Volatility in average selling prices for our semiconductor memory and storage products may adversely affect our business. We have experienced significant volatility in our average selling prices, including dramatic declines as noted in the table below, and may continue to experience such volatility in the future. In some prior periods, average selling prices for our products have been below our manufacturing costs and we may experience such circumstances in the future. Average selling prices for our products that decline faster than our costs could have a material adverse effect on our business, results of operations, or financial condition.
table: DRAM NAND
table: (percentage change in average selling prices)
table: 2019 from 2018 (30)% (44)%
table: 2018 from 2017 37% (8)%
table: 2017 from 2016 19% (7)%
table: 2016 from 2015 (35)% (19)%
table: 2015 from 2014 (11)% (15)%
question: Analyse this data from a financial earnings document. What is the ratio of percentage change in average selling prices of DRAM in '2017 from 2016' to '2018 from 2017'?