Question: When did the coach who  previously held coaching positions at Portland State, Miami, become the head coach for the athletic teams that represent Texas Tech University?

Context articles: Robin Pflugrad
2013–14 Texas Tech Lady Raiders basketball team
Dean Keener
Charlie Sadler
Kellyn Tate
Texas Tech Red Raiders cross country
2014–15 Texas Tech Lady Raiders basketball team
2015 Texas Tech Red Raiders baseball team
2015–16 Texas Tech Lady Raiders basketball team
Texas Tech Red Raiders and Lady Raiders

Robin Pflugrad (born November 29, 1958) is an American football coach.
 He is currently the head coach at Phoenix College.
 He was the head coach for the University of Montana from 2010 to 2011 and the offensive coordinator at Weber State University in 2013.
 Pflugrad previously held assistant coaching positions at Montana, Oregon, Washington State, Arizona State, and Portland State.
 During the 2014 football season he worked as a college football analyst for KTVX-TV, the CBS affiliate in Phoenix, Ariz., and as a football columnist for Cougfan.com, the Scout.com network affiliate covering Washington State University.
 Pflugrad also operates Pflugrad Athletic Consulting, offering administrative and strategic insights to high school and college athletic programs in the Southwest region.
The 2013–14 Texas Tech Lady Raiders basketball team will represent Texas Tech University in the 2013–14 college basketball season.
 It will be head coach Candi Whitaker's first season at Texas Tech.
 The Lady Raiders, are members of the Big 12 Conference and will play their home games at the United Spirit Arena.
 They finished with the season with a record of 6–24 overall, 0–18 in Big 12 play to finish in last place.
 They lost in the first round to TCU in the 2014 Big 12 Women's Basketball Tournament.
Dean Keener (born September 18, 1965) is the former head coach for the men's basketball team at James Madison University.
 He is a 1988 graduate of Davidson College where he served as a team captain and played on Davidson's 1986 NCAA Tournament team.
 Keener was hired on April 1, 2004.
 Keener previously held coaching positions at Drake University, Southern California, Virginia Tech, SMU, and Georgia Tech.
 Keener played an instrumental role in recruiting and developing many of the players on the 2004 national runner-up Georgia Tech squad.
 Keener resigned from his coaching position at JMU on February 22, 2008.
 After his resignation, he continued to coach for the remainder of the 2008 season.
 During his 20-year coaching career, he coached and/or recruited 12 players that played in the NBA, including Chris Bosh, Jarrett Jack, Anthony Morrow and Will Bynum.
 He is currently a color analyst for ESPN3.
Charlie Sadler (born May 6, 1949) is an American football coach and former player.
 Sadler was the 18th head college football coach for the Northern Illinois University, a position he held from 1991 to 1995.
 His career coaching record at Northern Illinois was 18 wins, 37 losses, and 0 ties, which ranks him eighth at Northern Illinois in total wins and 17th at Northern Illinois in winning percentage.
 Sadler was the defensive ends coach at Texas Tech from 2003 to 2009.
 He previously held coaching positions at the University of Oklahoma, the University of Missouri, and Iowa State University.
Kellyn Tate (born c. 1976), is an American softball coach and former player.
 She has been the head softball coach at University of Puget Sound since 2012.
 She previously held coaching positions at Portland State, Miami (Ohio), Texas Tech, and Penn State.
The Texas Tech Red Raiders men's and women's cross country teams represent Texas Tech University, often referred to as Texas Tech.
 The teams compete as members of the Big 12 Conference in the National Collegiate Athletic Association (NCAA).
 The women's cross country team is only one of three teams to win the Big 12 Conference title since the conference was formed in 1996.
The 2014–15 Texas Tech Lady Raiders basketball team will represent Texas Tech University in the 2014–15 college basketball season.
 It will be head coach Candi Whitaker's second season at Texas Tech.
 The Lady Raiders, were members of the Big 12 Conference and will play their home games at the United Supermarkets Arena.
 They finished the season 15–16, 5–13 in Big 12 play to finish in last place.
 They lost in the first round of Big 12 Women's Tournament to West Virginia.
The 2015 Texas Tech Red Raiders baseball team will represent Texas Tech University during the 2015 NCAA Division I baseball season.
 The Red Raiders will play their home games at Dan Law Field at Rip Griffin Park as a member of the Big 12 Conference.
 They will be led by head coach Tim Tadlock, in his 3rd season at Texas Tech.
The 2015–16 Texas Tech Lady Raiders basketball team will represent Texas Tech University in the 2015–16 college basketball season.
 It will be head coach Candi Whitaker's third season at Texas Tech.
 The Lady Raiders, were members of the Big 12 Conference and will play their home games at the United Supermarkets Arena.
 They finished the season 13–18, 3–15 in Big 12 play to finish in ninth place.
 They advanced to the quarterfinals of the Big 12 Women's Tournament where they lost to Baylor.
The Texas Tech Red Raiders and Lady Raiders are the athletic teams that represent Texas Tech University.
 The women's basketball team uses the name Lady Raiders, while the school's other women's teams use the "Red Raiders" name.