Context: In 2004, worldwide sales of audio CDs, CD-ROMs and CD-Rs reached about 30 billion discs. By 2007, 200 billion CDs had been sold worldwide. CDs are increasingly being replaced by other forms of digital storage and distribution, with the result that audio CD sales rates in the U.S. have dropped about 50% from their peak; however, they remain one of the primary distribution methods for the music industry. In 2014, revenues from digital music services matched those from physical format sales for the first time.

Question: In what year were digital and physical music sales the same?
Answer: 2014

Question: How many CDs had been distrubuted worldwide by 2007?
Answer: 200 billion

Question: What percent decrease did audio CD sales experience?
Answer: 50%

Question: How many CDs had been distrubuted around the world by 2007?
Answer: 200 billion

Question: In 2004 how many CDs had been sold around the world?
Answer: 30 billion

Question: What year did digital media begin to replace CDs?
Answer: Unanswerable

Question: How many CDs had been sold in the US by 2007?
Answer: Unanswerable

Question: In what year did CD sales peak?
Answer: Unanswerable

Question: Why are CD sales doing better than digital storage services?
Answer: Unanswerable

Question: How have CD sales changed internationally?
Answer: Unanswerable