Passage: During first week of publication, Fallout 3 beat all previous Fallout chapters' combined sales, making 57% stronger sales than the first week's performance of Bethesda's The Elder Scrolls IV: Oblivion in 2006. From its release in October to the end of 2008, Fallout 3 shipped over 4.7 million units. According to NPD Group, as of January 2009, the Xbox 360 version had sold 1.14 million units, and the PlayStation 3 version had sold 552,000 units. The Xbox 360 version was the 14th best-selling game of December 2008 in the United States, while the PlayStation 3 version was the 8th best-selling PlayStation 3 game in that region and month. The Xbox 360 version received a "Platinum" sales award from the Entertainment and Leisure Software Publishers Association (ELSPA), indicating sales of at least 300,000 copies in the United Kingdom.Fallout 3 was one of the most played titles in Xbox Live in 2009 and Games for Windows – Live in 2009, 2011, and 2012. In June 2015, following Fallout 4's announcement at Electronic Entertainment Expo, Fallout 3's sales were boosted up to 1000%. In November 2015, Electronic Entertainment Design and Research, a market research firm, estimated that the game had sold 12.4 million copies worldwide.

Question: Which number of Fallout was it?
3