Please answer a question about the following article about IPod:

On October 21, 2008, Apple reported that only 14.21% of total revenue for fiscal quarter 4 of year 2008 came from iPods. At the September 9, 2009 keynote presentation at the Apple Event, Phil Schiller announced total cumulative sales of iPods exceeded 220 million. The continual decline of iPod sales since 2009 has not been a surprising trend for the Apple corporation, as Apple CFO Peter Oppenheimer explained in June 2009: "We expect our traditional MP3 players to decline over time as we cannibalize ourselves with the iPod Touch and the iPhone." Since 2009, the company's iPod sales have continually decreased every financial quarter and in 2013 a new model was not introduced onto the market.

Which was the first year since iPod's introduction that no new model was released?
2013