Autechre () are an English electronic music duo consisting of Rob Brown and Sean Booth, both from Rochdale, Greater Manchester. Formed in 1987, they are one of the most popular acts signed to UK electronic label Warp Records, through which all of Autechre's full-length albums have been released beginning in 1993 with Incunabula. They have also worked closely with the label Skam. The music of Autechre has shifted gradually throughout their career, from their earlier work's roots in techno, electro, and hip hop to later albums often considered experimental in nature, featuring complex drum programming, subdued melodies, and few stylistic conventions.

Their ninth album, Quaristice, was released in early 2008. In contrast to Untilted, it is made up of twenty tracks, more than any other Autechre release, each typically around 2-5 minutes in length. The download-only Quaristice.Quadrange.ep.ae EP that accompanies it (as well as the Versions bonus disc and three tracks released exclusively through the Japanese iTunes Store) brings the total length of music released during their Quaristice era to over five hours. Among this is the hour-long "Perlence subrange 6-36" that closes the EP. Each track on Quaristice was edited down from lengthy improvised sessions between Booth and Brown, some of which were released in longer versions on Quaristice. Quadrange.ep.ae. Although Sean Booth has stated that the FLAC release of Quaristice is the actual product, the album was also released by Warp Records as a double LP and a single CD as well as an elaborate two CD edition by Warp Records. Limited to only 1000 copies, and containing both the regular album and Quaristice (Versions), this special edition was packaged in a photo-etched steel case. It sold out within 12 hours of being announced.  On 13 January 2010, Warp Records announced Oversteps, Autechre's tenth album. Originally slated to be released in March, it was released a month early in digital form on Bleep.com to those who preordered it; the CD and deluxe vinyl editions were released on 22 March 2010. A two-month European tour occurred in support of the album, followed by limited shows in Japan and Australia, the latter breaking a 15-year absence. Autechre then compiled a mix for the magazine FACT, released in February of the same year, that consisted of tracks by artists such as J Dilla and Necrophagist. On 25 May 2010, Warp Records announced the ten track Move of Ten, an EP by the duo in conjunction with the release of Oversteps. The digipack CD and the two 12" vinyl version, as well as a digital download, was released on 12 July 2010.  In April 2011 a boxset of EPs entitled EPs 1991 - 2002 (excluding Move of Ten) was released, with artwork from the Designers Republic. It includes a CD copy of their debut EP, Cavity Job, the first time it has been released on the format. In 2011 as part of Warp's 'Made in Japan' relief concert for the victims of the 2011 Sendai earthquake, an eleven-minute piece was released entitled '6852', possibly part of a previous live recording.  The eleventh studio album entitled Exai was released on 5 March 2013, having been available for download from the official website as of Valentine's Day, 14 February 2013. The duo announced their 14th EP L-Event on 17 September 2013, which was released on 28 October 2013.Answer this question using a quote from the following article:

When was Exai released?
The eleventh studio album entitled Exai was released on 5 March 2013,