In $2003,$ a typical USB solid state

drive $($SSD$)$ had a capacity of $128$ megabytes $(1\mathrm{.}28$ x $10^8$ bytes$)$ and cost $ $33.$ In

$2016,$ one could buy a USB solid state drive $($SSD$)$ with a capacity of $64$ gigabytes

$(6\mathrm{.}4$ x $10^10$ bytes$)$ for $ $15.$ Based on this data, calculate the annual average rate of

in$$ation in the price of SSD memory.