Question: In what year became publicly known that the 67th Unitades States Secretary of States had used her family's private email server for official communications?

<P0-S0> Hillary Clinton served as the 67th United States Secretary of State, under President Barack Obama, from 2009 to 2013, overseeing the department that conducted the Foreign policy of Barack Obama. <SEP> <P1-S0> David Evan Kendall (born 1944 ) is an American attorney, a graduate of Yale Law School and Oxford University, who clerked with Supreme Court Justice Byron White, worked as associate counsel at the NAACP Legal Defense Fund, and has been a partner at Williams & Connolly LLP of Washington, DC since 1981, where he has provided legal counsel to individuals and corporations on high-profile business and political matters. <P1-S1>  He is well known for his roles in the "Coker v. Georgia, Gilmore v. Utah," and other death penalty cases; in the "MGM et al. v. Grokster, et al." and "Tasini et al v. AOL" copyright and contract cases; as well as for various First Amendment cases, including for "The Washington Post." <P1-S2>  In addition, he is known for having advised President Bill Clinton during the Lewinsky scandal, and representing him during his impeachment trial. <P1-S3>  He served as defense attorney in the successful defense of retired General David Petraeus, and currently represents the former Secretary of State, Hillary Clinton, including in the matter of her use of a private email server while serving as U.S. Secretary of State. <SEP> <P2-S0> In March 2015, it became publicly known that Hillary Clinton, during her tenure as United States Secretary of State, had used her family's private email server for official communications, rather than official State Department email accounts maintained on federal secure servers. <P2-S1>  Those official communications included over 100 emails which contained classified information at the time they were sent, as well as nearly 2,100 emails which were not marked classified but would retroactively be ranked as classified by the State Department. <SEP> <P3-S0> During the 2007 Congressional investigation of the dismissal of eight U.S. attorneys, it was discovered that administration officials had been using a private Internet domain, called gwb43.com, owned by and hosted on an email server run by the Republican National Committee, for various official communications. <P3-S1>  The domain name is an abbreviation for "George W. Bush, 43rd" President of the United States. <P3-S2>  The use of this email domain became public when it was discovered that J. Scott Jennings, the White House's deputy director of political affairs, was using a gwb43.com email address to discuss the firing of the U.S. attorney for Arkansas. <P3-S3>  Communications by federal employees were also found on georgewbush.com (registered to "Bush-Cheney '04, Inc.") and rnchq.org (registered to "Republican National Committee"). <P3-S4>  Congressional requests for administration documents while investigating the dismissals of the U.S. attorneys required the Bush administration to reveal that not all internal White House emails were available. <P3-S5>  Conducting governmental business in this manner is a possible violation of the Presidential Records Act of 1978. <P3-S6>  Over 5 million emails may have been lost. <P3-S7>  Greg Palast claims to have come up with 500 of the Karl Rove emails, leading to damaging allegations. <P3-S8>  In 2009, it was announced that as many as 22 million emails may have been lost.