The previous year's World Champion has number 1, his team mate has number 2. Nigel Mansell was the World Champion for Williams in 1993, but did not race in 1994, so Alain Prost retained the number 2, but new driver Damon Hill used number zero, only ever previously used by Jody Scheckter in 1973. Bizarrely, Alain Prost won the title in 1994 but did not race in 1995, so Hill once again carried the number zero when Ayrton Senna joined the team as top driver.
