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:
| Race Name | Circuit | Date | Winning driver | Constructor | Report |
| --- | --- | --- | --- | --- | --- |
| Gran Premio Ciudad de Buenos Aires | Buenos Aires | 30 January | Juan Manuel Fangio | Mercedes | Report |
| VII Gran Premio del Valentino | Valentino Park | 27 March | Alberto Ascari | Lancia | Report |
| XVI Pau Grand Prix | Pau | 11 April | Jean Behra | Maserati | Report |
| III Glover Trophy | Goodwood | 11 April | Roy Salvadori | Maserati | Report |
| IV Grand Prix de Bordeaux | Bordeaux | 25 April | Jean Behra | Maserati | Report |
| VII BRDC International Trophy | Silverstone | 7 May | Peter Collins | Maserati | Report |
| VIII Gran Premio di Napoli | Posillipo | 8 May | Alberto Ascari | Lancia | Report |
| XVII Grand Prix d'Albi | Albi | 29 May | André Simon | Maserati | Report |
| III Curtis Trophy | Snetteron | 29 May | Roy Salvadori | Maserati | Report |
| III Cornwall MRC Formula 1 Race | Davidstow | 30 May | Leslie Marr | Connaught - Alta | Report |
| III London Trophy | Crystal Palace | 30 July | Mike Hawthorn | Maserati | Report |
| III Daily Record Trophy | Charterhall | 6 August | Bob Gerard | Maserati | Report |
| III RedeX Trophy | Snetterton | 13 August | Harry Schell | Vanwall | Report |
| II Daily Telegraph Trophy | Aintree | 3 September | Roy Salvadori | Maserati | Report |
| II International Gold Cup | Oulton Park | 24 September | Stirling Moss | Maserati | Report |
| I Avon Trophy | Castle Combe | 1 October | Harry Schell | Vanwall | Report |
Question:
How many constructors won the III Redex Trophy?
Answer:
1.0