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:
| Year | Team | Co-Drivers | Car | Class | Laps | Pos. | Class\nPos. |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1972 | Ford Motor Company Deutschland | Jochen Mass | Ford Capri 2600RS | S\n3.0 | 152 | DNF | DNF |
| 1973 | BMW Motorsport | Chris Amon | BMW 3.0CSL | T\n5.0 | 160 | DNF | DNF |
| 1980 | BMW Motorsport GmbH | Hans-Georg Bürger\n Dominique Lacaud | BMW M1 | IMSA | 283 | 15th | 5th |
| 1981 | BASF Cassetten Team GS Sport | Jean-Pierre Jarier\n Helmut Henzler | BMW M1 | IMSA\nGTX | 57 | DNF | DNF |
| 1982 | BASF Cassetten Team GS Sport | Jean-Louis Schlesser\n Dieter Quester | Sauber SHS C6-Ford | C | 76 | DNF | DNF |
| 1985 | Rothmans Porsche | Derek Bell | Porsche 962C | C1 | 367 | 3rd | 3rd |
| 1986 | Rothmans Porsche | Derek Bell\n Al Holbert | Porsche 962C | C1 | 368 | 1st | 1st |
| 1987 | Rothmans Porsche AG | Derek Bell\n Al Holbert | Porsche 962C | C1 | 368 | 1st | 1st |
| 1988 | Porsche AG | Klaus Ludwig\n Derek Bell | Porsche 962C | C1 | 394 | 2nd | 2nd |
| 1989 | Joest Racing | Bob Wollek | Porsche 962C | C1 | 382 | 3rd | 3rd |
| 1990 | Joest Porsche Racing | Derek Bell\n Frank Jelinski | Porsche 962C | C1 | 350 | 4th | 4th |
| 1991 | Konrad Motorsport | Derek Bell\n Frank Jelinski | Porsche 962C | C2 | 347 | 7th | 7th |
| 1993 | Le Mans Porsche Team | Walter Röhrl\n Hurley Haywood | Porsche 911 Turbo S LM-GT | GT | 79 | DNF | DNF |
| 1994 | Le Mans Porsche Team\n Joest Racing | Thierry Boutsen\n Danny Sullivan | Dauer 962 Le Mans | GT1 | 343 | 3rd | 2nd |
| 1995 | Porsche Kremer Racing | Thierry Boutsen\n Christophe Bouchut | Kremer K8 Spyder | WSC | 289 | 6th | 2nd |
| 1996 | Porsche AG | Thierry Boutsen\n Bob Wollek | Porsche 911 GT1 | GT1 | 353 | 2nd | 1st |
| 1997 | Porsche AG | Thierry Boutsen\n Bob Wollek | Porsche 911 GT1 | GT1 | 238 | DNF | DNF |
| 1998 | Team BMW Motorsport | Steve Soper\n Tom Kristensen | BMW V12 LM | LMP1 | 60 | DNF | DNF |
Question:
what is the total number of team ?
Answer:
18