In 2012, there was a 26% decline in sales worldwide from a maximum of 23.2 million in 2011. The reason given for this "alarmingly precipitous decline" was the rise of more general-purpose tablets that provided e-book reading apps along with many other abilities in a similar form factor. In 2013, ABI Research claimed that the decline in the e-reader market was due to the aging of the customer base. In 2014, the industry reported e-reader sales worldwide to be around 12 million, with only Amazon.com and Kobo Inc. distributing e-readers globally and various regional distribution by Barnes & Noble (US/UK), Tolino (Germany), Icarus (Netherlands), PocketBook International (Eastern Europe and Russia) and Onyx Boox (China and Vietnam). At the end of 2015, eMarketer estimated that there were 83.4 million e-reader users in the US, with the number predicted to grow by 3.5% in 2016. In late 2014, PricewaterhouseCoopers predicted that by 2018 e-books would make up over 50% of total consumer publishing revenue in the U.S. and UK, while at that time, e-books were over 30% of the share of revenue.