According to lead architect Mark Cerny, development of Sony's fourth video game console began as early as 2008.Less than two years earlier, the PlayStation 3 had launched after months of delays due to issues with production. The delay placed Sony almost a year behind Microsoft's Xbox 360, which was already approaching unit sales of 10 million by the time the PS3 launched. PlayStation Europe CEO Jim Ryan said Sony wanted to avoid repeating the same mistake with PS3's successor.In designing the system, Sony worked with software developer Bungie, who offered their input on the controller and how to make it better for shooting games. In 2012, Sony began shipping development kits to game developers, consisting of a modified PC running the AMD Accelerated Processing Unit chipset. These development kits were known as "Orbis".In early 2013, Sony announced that an event known as PlayStation Meeting 2013 would be held in New York City, U.S., on February 20, 2013, to cover the "future of PlayStation". Sony officially announced the PlayStation 4 at the event. It revealed details about the console's hardware and discussed some of the new features it would introduce. Sony also showed off real-time footage of games in development, as well as some technical demonstrations. The design of the console was unveiled in June at E3 2013, and the initial recommended retail prices of $399 (NA), €399 (Europe), and £349 (UK) given.The company revealed release dates for North America, Central America, South America, Europe, and Australia, as well as final pieces of information, at a Gamescom press event in Cologne, Germany, on August 20, 2013. The console was released on November 15, 2013, in the United States and Canada, followed by further releases on November 29, 2013. By the end of 2013, the PS4 was launched in more European, Asian and South American countries The PS4 released in Japan at ¥39,980 on February 22, 2014.Sony finalized a deal with the Chinese government in May 2014 to sell its products in mainland China, and the PS4 will be the first product to be released. Kazuo Hirai, chief executive officer of Sony, said in May: "The Chinese market, just given the size of it, is obviously potentially a very large market for video game products ... I think that we will be able to replicate the kind of success we have had with PS4 in other parts of the world in China."In September 2015, Sony reduced the price of the PS4 in Japan to ¥34,980, with similar price drops in other Southeast Asian markets. The first official sub £300 PS4 bundle was the £299.99 "Uncharted Nathan Drake Collection 500GB", released in the UK on October 9, 2015; a 1 TB £329.99 version was offered at the same time. On October 9, 2015, the first official price cut of the PS4 in North America was announced: a reduction of $50 to $349.99 (US) and by $20 to $429.99 (Canada). An official price cut in Europe followed in late October 2015, reduced to €349.99/£299.99.On June 10, 2016, Sony confirmed that a hardware revision of the PlayStation 4,  rumored to be codenamed "Neo", was under development. The new revision is a higher-end model that is meant to support gameplay in 4K. The new model will be sold alongside the existing model, and all existing software will be compatible between the two models. Layden stated that Sony has no plans to "bifurcate the market", only that gamers playing on the Neo will "have the same experience, but one will be delivered at a higher resolution, with an enhanced graphical experience, but everything else is going to be exactly as you'd expect". The high-end console was publicly revealed on September 7, 2016, as PlayStation 4 Pro. At the same time, Sony unveiled an updated version of the original PS4 model with a smaller form factor.In May 2018 during a presentation to investors, Sony Interactive Entertainment CEO John Kodera stated that the PlayStation 4 was heading into the end of its lifecycle, and that the company was anticipating decreasing year-over-yea

Question: How many Xbox 360's had already been sold when Playstations console was released?
Answer: 10 million