Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Number | Name | Titles | Date | Opponent | Result | Defenses |
| --- | --- | --- | --- | --- | --- | --- |
| 1.0 | Thomas Hearns | WBA Welterweight (147) | 1980-08-02 | Pipino Cuevas | TKO 2/15 | 3.0 |
| 1.0 | Thomas Hearns | WBC Light middleweight (154) | 1982-12-03 | Wilfred Benítez | TKO 2/15 | 5.0 |
| 1.0 | Thomas Hearns | The Ring Light middleweight (154) | 1983-05 | N/A | N/A | 5.0 |
| 1.0 | Thomas Hearns | WBC Light heavyweight (175) | 1987-03-07 | Dennis Andries | UD 12/12 | 0.0 |
| 1.0 | Thomas Hearns | WBC Middleweight (160) | 1987-10-29 | Juan Domingo Roldán | KO 4/12 | 0.0 |
| 2.0 | Ray Charles Leonard | WBC Welterweight (147) | 1979-11-30 | Wilfred Benítez | TKO 15/15 | 1.0 |
| 2.0 | Ray Charles Leonard | The Ring Welterweight (147) | 1979-11-30 | Wilfred Benítez | TKO 15/15 | 1.0 |
| 2.0 | Ray Charles Leonard | WBA Light middleweight (154) | 1981-06-25 | Ayub Kalule | TKO 9/15 | 0.0 |
| 2.0 | Ray Charles Leonard | The Ring Junior middleweight (154) | 1981-06-25 | Ayub Kalule | TKO 9/15 | 0.0 |
| 2.0 | Ray Charles Leonard | WBC Middleweight (160) | 1987-04-06 | Marvin Hagler | SD 12/12 | 0.0 |
| 2.0 | Ray Charles Leonard | The Ring Middleweight (160) | 1987-04-06 | Marvin Hagler | SD 12/12 | 0.0 |
| 2.0 | Ray Charles Leonard | WBC Super middleweight (168) | 1988-11-07 | Don Lalonde | TKO 9/12 | 2.0 |
| 2.0 | Ray Charles Leonard | WBC Light heavyweight (175) | 1988-11-07 | Don Lalonde | TKO 9/12 | 0.0 |
| 3.0 | Roberto Durán | WBA Lightweight (135) | 1972-06-26 | Ken Buchanan | TKO 13/15 | 12.0 |
| 3.0 | Roberto Durán | The Ring Lightweight (135) | 1972-06-26 | Ken Buchanan | TKO 13/15 | 12.0 |
| 3.0 | Roberto Durán | WBC Welterweight (147) | 1980-06-20 | Ray Charles Leonard | UD 15/15 | 0.0 |
| 3.0 | Roberto Durán | The Ring Welterweight (147) | 1980-06-20 | Ray Charles Leonard | UD 15/15 | 0.0 |
| 3.0 | Roberto Durán | WBA Light middleweight (154) | 1983-06-16 | Davey Moore | TKO 8/15 | 0.0 |
| 3.0 | Roberto Durán | WBC Middleweight (160) | 1989-02-24 | Iran Barkley | SD 12/12 | 0.0 |
| 4.0 | Pernell Whitaker | IBF Lightweight (135) | 1989-02-18 | Greg Haugen | UD 12/12 | 8.0 |
| 4.0 | Pernell Whitaker | The Ring Lightweight (135) | 1990-08-11 | Juan Nazario | KO 1/12 | 3.0 |
| 4.0 | Pernell Whitaker | IBF Junior Welterweight (140) | 1992-07-18 | Rafael Pineda | UD 12/12 | 0.0 |
| 4.0 | Pernell Whitaker | WBC Welterweight (147) | 1993-03-06 | James McGirt | UD 12/12 | 8.0 |
| 4.0 | Pernell Whitaker | Lineal Welterweight (147) | 1993-03-06 | James McGirt | UD 12/12 | 8.0 |
| 4.0 | Pernell Whitaker | WBA Super welterweight (154) | 1995-03-04 | Julio César Vásquez | UD 12/12 | 0.0 |
| 5.0 | Oscar De La Hoya | WBO Super featherweight (130) | 1994-03-05 | Jimmy Bredahl | TKO 10/12 | 1.0 |
| 5.0 | Oscar De La Hoya | WBO Lightweight (135) | 1995-02-18 | John-John Molina | UD 12/12 | 6.0 |
| 5.0 | Oscar De La Hoya | WBC Super lightweight (140) | 1996-06-07 | Julio César Chávez | TKO 4/12 | 1.0 |
| 5.0 | Oscar De La Hoya | Lineal Super lightweight (140) | 1996-06-07 | Julio César Chávez | TKO 4/12 | 1.0 |
| 5.0 | Oscar De La Hoya | WBC Welterweight (147) | 1997-04-12 | Pernell Whitaker | UD 12/12 | 7.0 |
| 5.0 | Oscar De La Hoya | Lineal Welterweight (147) | 1997-04-12 | Pernell Whitaker | UD 12/12 | 7.0 |
| 6.0 | Leo Gamez | WBA Minimumweight (105) | 1988-01-10 | Bong Jun Kim | UD 12/12 | 1.0 |
| 6.0 | Leo Gamez | WBA Light flyweight (108) | 1993-10-21 | Shiro Yahiro | TKO 9/12 | 3.0 |
| 6.0 | Leo Gamez | WBA Flyweight (112) | 1999-03-13 | Hugo Rafael Soto | KO 3/12 | 0.0 |
| 6.0 | Leo Gamez | WBA Super flyweight (115) | 1999-03-13 | Hideki Todaka | KO 7/12 | 0.0 |
| 7.0 | Roy Jones Jr. | IBF Middleweight (160) | 1993-05-22 | Bernard Hopkins | UD 12/12 | 1.0 |
| 7.0 | Roy Jones Jr. | IBF Super middleweight (168) | 1993-10-21 | James Toney | UD 12/12 | 5.0 |
| 7.0 | Roy Jones Jr. | WBC Light heavyweight (175) | 1997-08-07 | Montell Griffin | KO 1/12 | 11.0 |
| 7.0 | Roy Jones Jr. | The Ring Light heavyweight (175) | 2001 | N/A | N/A | 11.0 |
| 7.0 | Roy Jones Jr. | WBA Heavyweight (200+) | 2003-03-01 | John Ruiz | UD 12/12 | 0.0 |
| 8.0 | Floyd Mayweather, Jr. | WBC Super featherweight (130) | 1998-10-03 | Genaro Hernandez | RTD 8/12 | 8.0 |
| 8.0 | Floyd Mayweather, Jr. | Lineal Super featherweight (130) | 1998-10-03 | Genaro Hernandez | RTD 8/12 | 8.0 |
| 8.0 | Floyd Mayweather, Jr. | WBC Lightweight (135) | 2002-04-20 | José Luis Castillo | UD 12/12 | 3.0 |
| 8.0 | Floyd Mayweather, Jr. | The Ring Lightweight (135) | 2002-04-20 | José Luis Castillo | UD 12/12 | 3.0 |
| 8.0 | Floyd Mayweather, Jr. | WBC Super lightweight (140) | 2005-06-25 | Arturo Gatti | TKO 6/12 | 0.0 |
| 8.0 | Floyd Mayweather, Jr. | IBF Welterweight (147) | 2006-04-08 | Zab Judah | UD 12/12 | 0.0 |
| 8.0 | Floyd Mayweather, Jr. | The Ring Welterweight (147) | 2006-11-04 | Carlos Baldomir | UD 12/12 | 1.0 |
| 9.0 | Manny Pacquiao | WBC Flyweight (112) | 1998-12-04 | Chatchai Sasakul | KO 8/12 | 1.0 |
| 9.0 | Manny Pacquiao | Lineal Flyweight (112) | 1998-12-04 | Chatchai Sasakul | KO 8/12 | 1.0 |
| 9.0 | Manny Pacquiao | IBF Super Bantamweight (122) | 2001-06-23 | Lehlohonolo Ledwaba | KO 6/12 | 4.0 |
| 9.0 | Manny Pacquiao | The Ring Featherweight (126) | 2003-11-15 | Marco Antonio Barrera | TKO 11/12 | 2.0 |
| 9.0 | Manny Pacquiao | WBC Super featherweight (130) | 2008-03-15 | Juan Manuel Márquez | SD 12/12 | 0.0 |
| 9.0 | Manny Pacquiao | The Ring Junior lightweight (130) | 2008-03-15 | Juan Manuel Márquez | SD 12/12 | 0.0 |
| 10.0 | Érik Morales | WBC Super bantamweight (122) | 1997-09-06 | Daniel Zaragoza | KO 11/12 | 9.0 |
| 10.0 | Érik Morales | WBC Featherweight (126) | 2001-02-17 | Guty Espadas Jr. | UD 12/12 | 1.0 |
| 10.0 | Érik Morales | WBC Super featherweight (130) | 2004-02-28 | Jesus Chavez | UD 12/12 | 1.0 |
| 10.0 | Érik Morales | WBC Light welterweight (140) | 2011-09-17 | Pablo Cesar Cano | TKO 10/12 | 0.0 |
| 11.0 | Jorge Arce | WBO Light flyweight (108) | 1998-12-05 | Juan Domingo Cordoba | UD 12/12 | 1.0 |
| 11.0 | Jorge Arce | WBO Super flyweight (115) | 2010-01-30 | Angky Angkota | TD 7/12 | 0.0 |
| 11.0 | Jorge Arce | WBO Super bantamweight (122) | 2011-05-07 | Wilfredo Vazquez, Jr. | TKO 12/12 | 1.0 |
| 11.0 | Jorge Arce | WBO Bantamweight (118) | 2011-11-26 | Angky Angkota | UD 12/12 | 0.0 |
| 12.0 | Nonito Donaire | IBF Flyweight (112) | 2007-07-07 | Vic Darchinyan | TKO 5/12 | 3.0 |
| 12.0 | Nonito Donaire | WBA Super flyweight * (115) | 2009-08-15 | Rafael Concepcion | UD 12/12 | 2.0 |
| 12.0 | Nonito Donaire | WBC Bantamweight (118) | 2011-02-19 | Fernando Montiel | KO 2/12 | 1.0 |
| 12.0 | Nonito Donaire | WBO Super bantamweight (122) | 2012-02-04 | Wilfredo Vázquez, Jr. | SD 12/12 | 0.0 |
| 13.0 | Juan Manuel Márquez | IBF Featherweight (126) | 2003-02-01 | Manuel Medina | TKO 7/12 | 4.0 |
| 13.0 | Juan Manuel Márquez | WBC Super featherweight (130) | 2007-03-17 | Marco Antonio Barrera | UD 12/12 | 1.0 |
| 13.0 | Juan Manuel Márquez | The Ring Lightweight (135) | 2008-09-13 | Joel Casamayor | TKO 11/12 | 3.0 |
| 13.0 | Juan Manuel Márquez | WBO Light welterweight (140) | 2012-04-14 | Serhiy Fedchenko | UD 12/12 | 0.0 |
| 14.0 | Robert Guerrero | IBF Featherweight (126) | 2006-09-02 | Eric Aiken | RTD 8/12 | 2.0 |
| 14.0 | Robert Guerrero | IBF Super featherweight (130) | 2009-08-22 | Malcolm Klassen | UD 12/12 | 0.0 |
| 14.0 | Robert Guerrero | WBA & WBO Lightweight * (135) | 2011-04-09 | Michael Katsidis | UD 12/12 | 0.0 |
Question:
How many times was pernell whitaker an opponent?
Answer:
2.0