Rider deaths in motorcycle racing

Columns: Year | Rider | Circuit | Race
1971 | Herman Hertsens | Circuit Maashaven | 24 Hours of Oss | 1971 | Lambert Schuurmans | Circuit Maashaven | 24 Hours of Oss | 1972 | Claude Romain | Zolder | 24 Hours of Liège | 1973 | Francisco Cufí | Montjuïc | 24 Horas de Montjuïc | 1975 | Hans Hutten | Circuit Maashaven | 24 Hours of Oss | 1976 | Francisco Teixeira | Interlagos | 24 Horas de Interlagos | 1976 | Gilbert Lavelle | Bugatti | Bol d'Or

Example questions:
In what year was there a motorcycle death at the circuit that hosts the German Grand Prix ? | When was an F1 race last held on the circuit to see the most motorcycle deaths ? | Who operates the circuit that hosts a motorcycle race to take place over eight consecutive hours ? | What motorcycle race is held at the circuit that was shortened due to safety concerns in 1979 ? | How long is the circuit that caused a motorcycle racing death in 1972 ?

Answers:
1986 | 1975 | Mobilityland Corporation | 24 Hours of Liège | 4.011 km