entry-priced iPhones and the addition of a significant new carrier in the second quarter of 2014. 

The growth in net sales in the Greater China segment during 2013 resulted from two major iPhone introductions during the year, iPhone 5 in December 2012 and iPhone 5c and iPhone 5s in September 2013. Further contributing to the growth in 2013 was the introduction of the fourth generation iPad and iPad mini during the second quarter of 2013 and an increase in iPhone channel inventory as of the end of 2013 compared to the end of 2012. While net sales in the Greater China segment were up 13% for all of 2013, net sales for the second half of 2013 declined 4% compared to the second half of 2012. 

In 2014 the Japan segment generated year-over-year increases in net sales and unit sales of every major product category except iPod and experienced growth in net sales of iTunes, Software and Service. The year-over-year growth in iPhone was driven by the successful launch of iPhone 5s and 5c in September 2013, the successful launch of iPhone 6 and 6 Plus in September 2014, increased demand for the Company’s entry-priced iPhones and the addition of a significant new carrier in the fourth quarter of 2013. These positive factors were partially offset by weakness in the Japanese Yen relative to the U.S. dollar. 

The increase in net sales in the Japan segment during 2013 reflected significant increases in unit volumes of iPhone and iPad, strong growth of iTunes Store net sales and an increase in iPhone channel inventory as of the end of 2013 compared to the end of 2012. These positive factors were partially offset by declines in ASPs for iPhone and iPad and by weakness in the Japanese Yen relative to the U.S. dollar. 

Net sales in the Rest of Asia Pacific segment declined in 2014 compared to 2013 due to year-over-year reductions in net sales in all major product categories except Mac and reductions in unit sales of iPad and iPod. Net sales in 2014 were also negatively affected by the weakness in several foreign currencies relative to the U.S. dollar, including the Australian dollar. 

The year-over-year growth in Rest of Asia Pacific segment net sales during 2013 was primarily driven by the launch of iPhone 5 and higher sales from the iTunes Store, partially offset by a decrease in net sales of iPad and Mac. 

The growth in Retail segment net sales in 2014 was primarily driven by increases in net sales and unit sales of iPhone and Mac, partially offset by declines in net sales and unit sales of iPad and iPod. With an average of 424 and 403 open stores during 2014 and 2013, respectively, average revenue per store increased to $50.6 million in 2014 from $50.2 million in 2013. 

The growth in Retail segment net sales during 2013 was primarily driven by increased unit sales of iPhone and iPad following the new product introductions in the first half of 2013 and increased sales of services. With an average of 403 and 365 open stores during 2013 and 2012, respectively, average revenue per store decreased to $50.2 million in 2013, compared to $51.5 million in 2012. 

The Retail segment’s operating income was $4.6 billion, $4.0 billion and $4.6 billion during 2014,