The line graph shows a music sales by three methods They are streams downloads and CDs purchased The data shows in nine years from 2011 to 2018

Overall, not all sales always increase. It only happens to streams. Meanwhile, sales with CDs have always decreased. On the other hand, the graph on download sales is unstable.
From 2011 to 2018 the number of sales increases with streams has always been stable. Likewise with the graph of the decline shown for sales with CDs. There is no drastic increase or decrease. 2018 was the highest sales achievement with streams which was 40% and the lowest figure of CDs sales was 25%. But sales with downloads are still only around 30-40.
The conclusion is sales with CDs and streams experience upwards and downwards graphs based on the times. While the download is still relevant to use, and does not experience a high or down level of sales.