Question: When did the senator who vacated a U.S. Senate seat which Thomas M. Davis considering a run for in 2008 serve as Secretary of the Navy?

Context paragraphs:
Johnnie Byrd: Johnnie B. Byrd, Jr. (born February 8, 1951 in Brewton, Alabama) was a member of the Florida House of Representatives from District 62 representing Eastern Hillsborough County from 1996 through 2004.  He was speaker of the House from 2002-2004.  In 2004, Byrd made an unsuccessful run for the U.S. Senate seat vacated by retiring Senator Bob Graham as a Republican candidate.  He was fourth in a field of six with 68,982 votes, 5.9 percent of the vote.  Mel Martinez won the primary and the general election.  Prior public service included a spell as a school board member of the Brewton City School System in Brewton, Alabama.

Foster Campbell: Foster Lonnie Campbell Jr. (born January 6, 1947), is an American politician and member of the Democratic Party from the U.S. state of Louisiana.  Since 2003, he has been a member of the Louisiana Public Service Commission.  He served in the Louisiana State Senate from 1976 to 2002 and was an unsuccessful candidate for governor in the 2007 election against the Republican Bobby Jindal.  He has also run unsuccessfully for the United States House of Representatives for Louisiana's 4th congressional district three times: in 1980, 1988, and 1990, and in 2016, was an unsuccessful candidate for the open U.S. Senate seat vacated by incumbent Republican David Vitter.

John Warner: John William Warner (born February 18, 1927) served as Secretary of the Navy from 1972 to 1974 and as a five-term Republican United States Senator from Virginia from January 2, 1979, to January 3, 2009.  He did not seek reelection in 2008.  He works for the law firm of Hogan Lovells, where he had previously worked before joining the United States Department of Defense.

Sharron Angle: Sharron Elaine Angle (born Sharron Elaine Ott; July 26, 1949) is an American politician who served as a Republican member of the Nevada Assembly from 1999 to 2007.  She ran unsuccessfully as the 2010 Republican nominee for the U.S. Senate seat in Nevada, garnering 45 percent of the vote.  On September 15, 2013 she was unanimously elected the fifth President of the National Federation of Republican Assemblies, and resigned in 2016 to run again for the Nevada U.S. Senator position being vacated by Harry Reid but failed to win the Republican primary.

Lula J. Davis: Lula Johnson Davis was Secretary for the Majority of the United States Senate from 2008 to 2011.  Davis was born in Louisiana.  She received a B.S. in office administration and an M.Ed., in guidance counseling from Southern University in Baton Rouge, Louisiana.  She began her career with the Senate as a legislative correspondent for Senator Russell B. Long of Louisiana.  After Senator Long retired from the Senate in January 1987, Davis worked as an office assistant for the Democratic Policy Committee’s Senate floor staff office.  In 1993, she became a member of the Democratic floor staff.  In 1995, she was promoted to chief floor assistant.  In 1997, she assumed the position of assistant secretary.  After the retirement of Martin P. Paone, in January 2008, the Senate elected Davis Secretary for the Majority.  As Secretary for the Majority, she was a senior procedural advisor to the Senate Majority Leader, Senator Harry Reid, and supervised the day-to-day Senate schedule.  In so doing, she often worked with Secretary for the Minority David J. Schiappa.  Davis told Senators what they could and could not do when it came to rules and procedure.  Consequently, Davis was called “one of the most powerful unelected people in the U.S. Senate.”  Davis retired at the end of the 111th Congress.

Tim Scott: Timothy Eugene Scott (born September 19, 1965) is an American former insurance agent and politician who is the junior United States Senator for South Carolina.  A Republican, he joined the Senate in 2013 when South Carolina Governor Nikki Haley appointed him to fill the U.S. Senate seat vacated by Jim DeMint.  Scott won a special election in 2014 for the final two years of DeMint's second term, and won election to a full term in 2016.

Philippine Senate election, 2013: The 2013 election to the Senate of the Philippines was the 31st election to the Senate of the Philippines.  It was held on Monday, May 13, 2013 to elect 12 of the 24 seats in the Senate.  Together with those elected in 2010, the candidates elected in this election shall comprise the 16th Congress.  The senators elected in 2010 will serve until June 30, 2016, while the senators elected in this election will serve up to June 30, 2019.  The elections to the House of Representatives as well as local elections occurred on the same date.  The Philippines use plurality-at-large voting for seats in the Senate: the twelve candidates with the highest number of votes win the twelve seats up for election.  The Senate seat vacated by President Benigno Aquino III in 2010 was among the twelve seats to be put for election.

Thomas M. Davis: Thomas Milburn "Tom" Davis III (born January 5, 1949) is a former Republican member of the United States House of Representatives, representing Virginia's 11th congressional district in Northern Virginia, and currently serves as the Rector and Professor at George Mason University.  Davis was considering a run for the U.S. Senate seat being vacated by five-term incumbent and fellow Republican John Warner in the 2008 election, but decided against it.  He announced on January 30, 2008, that he would not seek reelection to an eighth term.  Davis resigned from Congress on November 24, 2008.

United States Senate election in Indiana, 2010: The 2010 United States Senate election in Indiana took place on November 2, 2010, alongside 33 other elections to the United States Senate in other states and elections to the United States House of Representatives and various state and local elections to fill Indiana's class III United States Senate seat.  Incumbent Democratic U.S. Senator Evan Bayh decided in February 2010 to retire instead of seeking a third term shortly after former U.S. Senator Dan Coats announced his candidacy for Bayh's contested seat.  No Democratic candidate submitted enough signatures by the deadline to run, leading Democratic officials to choose U.S. Congressman Brad Ellsworth to be the nominee.  The Libertarian Party nominated YMCA instructor Rebecca Sink-Burris, who had previously run against Evan Bayh in the United States Senate election in Indiana, 1998 but with less success than in this election.  Republican nominee and former U.S. Senator Dan Coats won the open seat.

United States Senate election in New Jersey, 2006: The 2006 United States Senate election in New Jersey was held on November 7, 2006.  Incumbent Democratic U.S. Senator Bob Menendez was elected to represent New Jersey in the United States Senate for a six-year term which ended in January 2013.  The seat was previously held by Democratic Governor of New Jersey Jon Corzine.  After he stepped down from his Senate seat and was sworn in Governor, Corzine appointed Rep. Menendez, who was sworn in on January 18, 2006.  Menendez was challenged by Republican Thomas Kean, Jr. and seven other candidates.  Filing for the primary closed on April 10, 2006.  The primary election was held on June 6, 2006.  Menendez became the first Hispanic to hold a U.S. Senate seat from New Jersey, and was the first Latino elected to statewide office in the state.

Supporting paragraphs: Thomas M. Davis John Warner
Answer: 1972 to 1974