| Number | Begin | End | Name |
| 40 | May 2019 | June 2019 | Ethan R. Carden |
| 39 | May 2018 | May 2019 | Rodrigo A. Padilla Gonzalez |
| 38 | January 2018 | May 2018 | Matteo Barausse |
| 37 | January 2017 | January 2017 | Taylor Schick |
| 36 | January 2017 | January 2018 | Josh Peterson |
| 35 | December 2016 | January 2017 | Josh Peterson |
| 34 | December 2015 | December 2016 | Ryan Hancock |
| 33 | January 2015 | December 2015 | Tim J. Wyatt |
| 32 | January 2014 | January 2015 | Jacob Haar |
| 31 | December 2012 | January 2014 | Garrett R. Hill |
| 30 | January 2012 | December 2012 | Mitch L. Rittiman |
| 29 | December 2010 | January 2012 | Matthew S. Shull |
| 28 | January 2010 | December 2010 | Allan Cantrell |
| 27 | January 2009 | January 2010 | Kevin Baisch |
| 26 | May 2008 | January 2009 | Michael P. Browning |
| 25 | February 2007 | May 2008 | Justin Backes |
| 24 | January 2006 | February 2007 | Roy A. Chuning |
| 23 | January 2005 | January 2006 | Ryan Keever |
| 22 | December 2003 | January 2005 | Jason Milliron |
| 21 | February 2003 | December 2003 | Murray J. Kain |
| 20 | February 2002 | February 2003 | Joshua D. Foust |
| 19 | February 2001 | February 2002 | Steven F. M. Sharpe |
| 18 | March 2000 | February 2001 | Mr. Richard A. O'Connor III |
| 17 | March 1999 | March 2000 | Travis R. Nye |
| 16 | March 1998 | March 1999 | Alex J. Ivan III |
| 15 | November 1996 | March 1998 | Brian D. Brown |
| 14 | October 1995 | November 1996 | Troy A. Scott |
| 13 | April 1995 | October 1995 | Al P. VanDuyne |
| 12 | April 1994 | April 1995 | David S. Wood |
| 11 | November 1992 | November 1993 | Kevin N. Fowler |
| 10 | May 1992 | | Christopher A. Campbell |
| 9 | January 1992 | December 1992 | Hans F. Howland |
| 8 | January 1990 | December 1990 | Mr. Ed Wirthwein III |
| 7 | January 1972 | December 1972 | William J. Welbes |
| 5 | January 1971 | December 1972 | Thomas A. Fritz |
| 6 | January 1971 | December 1972 | Thomas A. Fritz |
| 4 | January 1967 | December 1968 | Fred M. Rosenberger |
| 3 | August 1963 | May 1964 | Mr. Jim L. Mallory |
| 1 | | | John M. Fay |
| 2 | | | Drew S. Hawkins |