The line graph illustrates the percentage of listeners who buy different types of music (streams,downloads and CDs purchased) from 2011 to 2018. Overall, the dominant type of music became streams in the final year, although their initial point was the lowest compare with other methods of sales. In contrast, CDs purchased music delivery was the most popular at the beginning of the period, then it got steadily went down every year. Moreover, downloads music sales repeated those trend with some fluctuations in the middle of the the period given.