Question: The circuit that held the Rothmans 50,000 hosted how many stagings of the British Grand Prix?

Context paragraphs:
2017 British Grand Prix: The 2017 British Grand Prix (formally known as the 2017 Formula 1 Rolex British Grand Prix) was a Formula One motor race that took place on 16 July 2017 at the Silverstone Circuit in Silverstone, United Kingdom.  This race was the seventy-second running of the British Grand Prix—the first having been held in 1926—and the tenth round of the 2017 Formula One season.  The race marked the fifty-second time that the race has been held at the Silverstone Circuit since the Formula One series inception in .

2000 British Grand Prix: The 2000 British Grand Prix (formally the LIII Foster's British Grand Prix) was a Formula One motor race held on 23 April 2000 at Silverstone Circuit, England, United Kingdom.  It was the fourth race of the 2000 Formula One season and the 53rd British Grand Prix.  The 60-lap race was won by McLaren driver David Coulthard after starting from fourth position.  His teammate Mika Häkkinen finished second with Michael Schumacher third for the Ferrari team.

2014 British Grand Prix: The 2014 British Grand Prix (formally the 2014 Formula 1 Santander British Grand Prix) was a Formula One motor race held on 6 July 2014 at the Silverstone Circuit in Silverstone, United Kingdom.  It was the ninth round of the 2014 Formula One season, and the 69th British Grand Prix.  The 52-lap race was won by Lewis Hamilton for the Mercedes team, from a sixth position start; the lowest position he has ever won from.  Valtteri Bottas finished second in a Williams car, with Daniel Ricciardo third for the Red Bull Racing team.  This race was the first to be red-flagged on lap one since the 2000 Monaco Grand Prix.

2015 British Grand Prix: The 2015 British Grand Prix (formally known as the 2015 Formula 1 British Grand Prix) was a Formula One motor race that took place on 5 July 2015 at the Silverstone Circuit in Silverstone, United Kingdom.  The race was the ninth round of the 2015 season, and marked the 70th running of the British Grand Prix, and the 51st time that the race was held at the Silverstone Circuit.

Brands Hatch: Brands Hatch is a motor racing circuit in West Kingsdown in Kent, England.  First used as a grasstrack motorcycle circuit on farmland, it hosted 12 runnings of the British Grand Prix between 1964 and 1986 and currently hosts many British and International racing events.

2012 European Grand Prix: The 2012 European Grand Prix (formally, the 2012 Formula 1 Grand Prix of Europe) was a Formula One motor race that was held at the Valencia Street Circuit in Valencia, Spain on 24 June 2012.  It was the eighth round of the 2012 championship season, and the final time the circuit hosted the European Grand Prix.  It was Fernando Alonso's second Grand Prix win in Spain after the 2006 Spanish Grand Prix held at Barcelona.  Michael Schumacher finished third at the age of 43 years and 173 days, the oldest to climb to the podium since Jack Brabham's second-place finish at the 1970 British Grand Prix.  It was Schumacher's best result since his comeback in 2010 and the final podium finish of his Formula One career.

2016 British Grand Prix: The 2016 British Grand Prix (formally known as the 2016 Formula 1 British Grand Prix) was a Formula One motor race that was held on 10 July 2016 at the Silverstone Circuit in Silverstone, United Kingdom.  This race was the seventy-first running of the British Grand Prix, the first having been held in 1926, and was the tenth round of the 2016 Formula One season and the fifty-second time that the race was held at the Silverstone Circuit since the Formula One series inception in .

1987 British Grand Prix: The 1987 British Grand Prix (formally the XL Shell Oils British Grand Prix) was a Formula One motor race held on 12 July 1987 at the Silverstone Circuit, Silverstone.  It was the seventh race of the 1987 Formula One season.  It was the 42nd British Grand Prix and the 23rd to be held at Silverstone.  The race was held over 65 laps of the five kilometre circuit for race distance of 311 kilometres.

Rothmans 50,000: The Rothmans 50,000 was a motor race held at the Brands Hatch circuit on 28 August 1972 with a prize fund of £50,000.

2009 British Grand Prix: The 2009 British Grand Prix (formally the 2009 Formula 1 Santander British Grand Prix) was a Formula One motor race held at the Silverstone Circuit in Northamptonshire, England on 21 June 2009.  The 60-lap race was the eighth round of the 2009 Formula One season.  It was scheduled to be the last British Grand Prix to be held at Silverstone, before the event moved to Donington Park for the 2010 season.  However, due to Donington being unable to raise the required funds the event returned to Silverstone again in 2010.  The race was won by Sebastian Vettel, who started on pole, with championship leader Jenson Button finishing in sixth position.

Supporting paragraphs: Rothmans 50,000 Brands Hatch
Answer: 12