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:
| Pos | Class | No | Team | Drivers | Chassis | Engine | Laps |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 17 | P\n5.0 | 19 | SpA Ferrari SEFAC | Günter Klass\n Peter Sutcliffe | Ferrari 330 P4 | Ferrari 4.0L V12 | 296 |
| 18 | P\n+5.0 | 57 | Shelby-American Inc. | Ronnie Bucknum\n Paul Hawkins | Ford GT40 Mk.IIB | Ford 7.0L V8 | 271 |
| 19 | P\n+5.0 | 7 | Chaparral Cars Inc. | Phil Hill\n Mike Spence | Chaparral 2F | Chevrolet 7.0L V8 | 225 |
| 20 | P\n1.3 | 47 | Société des Automobiles Alpine | Jean-Claude Andruet\n Robert Bouharde | Alpine A210 | Renault-Gordini 1.3L I4 | 219 |
| 21 | P\n5.0 | 23 | Maranello Concessionaires | Richard Attwood\n Piers Courage | Ferrari 412P | Ferrari 4.0L V12 | 208 |
| 22 | P\n1.15 | 56 | Ecurie Savin-Calberson | Gérard Larrousse\n Patrick Depailler | Alpine A210 | Renault-Gordini 1.0L I4 | 204 |
| 23 | P\n1.15 | 55 | North American Racing Team (NART) | Jean-Luc Thérier\n Francois Chevalier | Alpine M64 | Renault-Gordini 1.0L I4 | 201 |
| 24 | P\n+5.0 | 3 | Holman & Moody | Mario Andretti\n Lucien Bianchi | Ford GT40 Mk.IV | Ford 7.0L V8 | 188 |
| 25 | P\n+5.0 | 6 | Holman & Moody\n Ford France S.A. | Jo Schlesser\n Guy Ligier | Ford GT40 Mk.IIB | Ford 7.0L V8 | 183 |
| 26 | S\n5.0 | 16 | Ford France S.A. | Pierre Dumay\n Henri Greder | Ford GT40 Mk.I | Ford 4.7L V8 | 179 |
| 27 | P\n+5.0 | 5 | Holman & Moody | Roger McCluskey\n Frank Gardner | Ford GT40 Mk.IIB | Ford 7.0L V8 | 179 |
| 28 | GT\n+5.0 | 9 | Dana Chevrolet Inc. | Bob Bondurant\n Dick Guldstrand | Chevrolet Corvette | Chevrolet 7.0L V8 | 167 |
| 29 | P\n2.0 | 29 | Equipe Matra Sports | Jean-Pierre Beltoise\n Johnny Servoz-Gavin | Matra MS630 | BRM 2.0L V8 | 155 |
| 30 | P\n5.0 | 25 | North American Racing Team (NART) | Pedro Rodriguez\n Giancarlo Baghetti | Ferrari 412P | Ferrari 4.0L V12 | 144 |
| 31 | GT\n2.0 | 67 | Pierre Boutin | Pierre Boutin\n Patrice Sanson | Porsche 911S | Porsche 2.0L Flat-6 | 134 |
| 32 | GT\n2.0 | 60 | Philippe Farjon | Philippe Farjon\n André Wicky | Porsche 911S | Porsche 2.0L Flat-6 | 126 |
| 33 | S\n5.0 | 18 | Scuderia Filipinetti | Umberto Maglioli\n Mario Casoni | Ford GT40 Mk.I | Ford 4.7L V8 | 116 |
| 34 | P\n5.0 | 20 | SpA Ferrari SEFAC | Chris Amon\n Nino Vaccarella | Ferrari 330 P3 Spyder | Ferrari 4.0L V12 | 105 |
| 35 | P\n2.0 | 40 | Porsche System Engineering | Gerhard Mitter\n Jochen Rindt | Porsche 907/6L | Porsche 2.0L Flat-6 | 103 |
| 36 | P\n+5.0 | 8 | Chaparral Cars Inc. | Bob Johnson\n Bruce Jennings | Chaparral 2F | Chevrolet 7.0L V8 | 91 |
| 37 | P\n5.0 | 22 | Scuderia Filipinetti | Jean Guichet\n Herbert Müller | Ferrari 412P | Ferrari 4.0L V12 | 88 |
| 38 | P\n+5.0 | 4 | Holman & Moody | Denis Hulme\n Lloyd Ruby | Ford GT40 Mk.IV | Ford 7.0L V8 | 86 |
| 39 | P\n2.0 | 39 | Porsche System Engineering | Udo Schütz\n Joe Buzzetta | Porsche 910/6L | Porsche 2.0L Flat-6 | 84 |
| 40 | P\n1.15 | 58 | Société des Automobiles Alpine | Philippe Vidal\n Leo Cella | Alpine A210 | Renault-Gordini 1.0L I4 | 67 |
| 41 | P\n+5.0 | 14 | John Wyer Automotive Engineering | David Piper\n Richard Thompson | Mirage M1\n(Ford GT40 Lightweight) | Ford 5.7L V8 | 59 |
| 42 | GT\n5.0 | 17 | Claude Dubois | Claude Dubois\n Chris Tuerlinckx | Ford-Shelby Mustang GT350 | Ford 4.7L V8 | 58 |
| 43 | P\n2.0 | 30 | Equipe Matra Sports | Jean-Pierre Jaussaud\n Henri Pescarolo | Matra MS630 | BRM 2.0L V8 | 55 |
| 44 | P\n1.6 | 44 | Team Elite | David Preston\n John Wagstaff | Lotus Europa Mk.47 | Ford Cosworth 1.6L I4 | 42 |
| 45 | P\n1.15 | 53 | S.E.C. Automobiles CD | André Guilhaudin\n Alain Bertaut | CD SP66C | Peugeot 1.1L I4 | 35 |
| 46 | P\n5.0 | 26 | North American Racing Team (NART) | Ricardo Rodriguez\n Chuck Parsons | Ferrari 365 P2 | Ferrari 4.4L V12 | 30 |
| 47 | P\n+5.0 | 15 | John Wyer Automotive Engineering | Jacky Ickx\n Brian Muir | Mirage M1\n(Ford GT40 Lightweight) | Ford 5.7L V8 | 29 |
| 48 | P\n1.15 | 52 | S.E.C. Automobiles CD | Dennis Dayan\n Claude Ballot-Léna | CD SP66C | Peugeot 1.1L I4 | 25 |
| 49 | P\n+5.0 | 12 | Lola Cars Ltd. / Team Surtees | Peter de Klerk\n Chris Irwin | Lola T70 Mk.III | Aston Martin 5.0L V8 | 25 |
| 50 | S\n5.0 | 62 | John Wyer Automotive Engineering /\nViscount Downe | Mike Salmon\n Brian Redman | Ford GT40 Mk.I | Ford 4.7L V8 | 20 |
| 51 | P\n1.15 | 54 | Roger Nathan Racing Ltd. | Roger Nathan\n Mike Beckwith | Costin Nathan | Hillman 1.0L I4 | 15 |
| 52 | P\n1.3 | 50 | Marcos Racing Ltd. | Chris J. Lawrence\n Jem Marsh | Marcos Mini Marcos GT | BMC 1.3L I4 | 13 |
| 53 | P\n+5.0 | 11 | Lola Cars Ltd. / Team Surtees | John Surtees\n David Hobbs | Lola T70 Mk.III | Aston Martin 5.0L V8 | 3 |
| 54 | GT\n2.0 | 43 | "Franc" | Jacques Dewes\n Anton Fischhaber | Porsche 911S | Porsche 2.0L Flat-6 | 2 |
Question:
how many laps did ronnie bucknum complete?
Answer:
271