I want to know the answer to the following question:
Approximately what percentage of the hard drive-based music player sales does iPod have since 2004?
All the background I'm provided with is that "During the year from January 2004 to January 2005, the high rate of sales caused its U.S. market share to increase from 31% to 65% and in July 2005, this market share was measured at 74%.". Is that enough to answer the question?
Answer: no