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:
| Stage | Date | Route | Terrain | Length | Winner |
| --- | --- | --- | --- | --- | --- |
| P | 4 July | Boulogne-Billancourt | Individual time trial | km (mi) | Thierry Marie ( FRA ) |
| 1 | 5 July | Nanterre – Sceaux | Plain stage | km (mi) | Pol Verschuere ( BEL ) |
| 2 | 5 July | Meudon – Saint-Quentin-en-Yvelines | Team time trial | km (mi) | Système U |
| 3 | 6 July | Levallois-Perret – Liévin | Plain stage | km (mi) | Davis Phinney ( USA ) |
| 4 | 7 July | Liévin – Évreux | Plain stage | km (mi) | Pello Ruiz ( ESP ) |
| 5 | 8 July | Évreux – Villers-sur-Mer | Plain stage | km (mi) | Johan van der Velde ( NED ) |
| 6 | 9 July | Villers-sur-Mer – Cherbourg | Plain stage | km (mi) | Guido Bontempi ( ITA ) |
| 7 | 10 July | Cherbourg – Saint-Hilaire-du-Harcouët | Plain stage | km (mi) | Ludo Peeters ( BEL ) |
| 8 | 11 July | Saint-Hilaire-du-Harcouët – Nantes | Plain stage | km (mi) | Eddy Planckaert ( BEL ) |
| 9 | 12 July | Nantes | Individual time trial | km (mi) | Bernard Hinault ( FRA ) |
| 10 | 13 July | Nantes – Futuroscope | Plain stage | km (mi) | Jose-Angel Sarrapio ( ESP ) |
| 11 | 14 July | Poitiers – Bordeaux | Plain stage | km (mi) | Rudy Dhaenens ( BEL ) |
| 12 | 15 July | Bayonne – Pau | Stage with mountain(s) | km (mi) | Pedro Delgado ( ESP ) |
| 13 | 16 July | Pau – Superbagnères | Stage with mountain(s) | km (mi) | Greg LeMond ( USA ) |
| 14 | 17 July | Luchon – Blagnac | Stage with mountain(s) | km (mi) | Niki Rüttimann ( SUI ) |
| 15 | 18 July | Carcassonne – Nîmes | Plain stage | km (mi) | Frank Hoste ( BEL ) |
| 16 | 19 July | Nîmes – Gap | Hilly stage | km (mi) | Jean-François Bernard ( FRA ) |
| 17 | 20 July | Gap – Serre Chevalier | Stage with mountain(s) | km (mi) | Eduardo Chozas ( ESP ) |
| 18 | 21 July | Briançon – Alpe d'Huez | Stage with mountain(s) | km (mi) | Bernard Hinault ( FRA ) |
| 19 | 23 July | Villard-de-Lans – Saint-Étienne | Hilly stage | km (mi) | Julián Gorospe ( ESP ) |
| 20 | 24 July | Saint-Étienne | Individual time trial | km (mi) | Bernard Hinault ( FRA ) |
| 21 | 25 July | Saint-Étienne – Puy de Dôme | Hilly stage | km (mi) | Erich Mächler ( SUI ) |
| 22 | 26 July | Clermont-Ferrand – Nevers | Plain stage | km (mi) | Guido Bontempi ( ITA ) |
| 23 | 27 July | Cosne-sur-Loire – Paris ( Champs-Élysées ) | Plain stage | km (mi) | Guido Bontempi ( ITA ) |
Question:
Which stage took the tour through Boulogne-Billancourt?
Answer:
P