The answer I was looking for was 12. Someone else can have a go now...
1987 San Marino Grand Prix, Nigel Mansell, 14
1989 Hungarian Grand Prix, Nigel Mansell, 12
1990 Mexican Grand Prix, Alain Prost, 13
1992 Brazilian Grand Prix, Nigel Mansell, 16
1995 Belgian Grand Prix, Michael Schumacher, 16
1996 Monaco Grand Prix, Olivier Panis, 14
1999 European Grand Prix, Johnny Herbert, 14
2000 German Grand Prix, Rubens Barrichello, 18
2003 Australian Grand Prix, David Coulthard, 11
2004 Belgian Grand Prix, Kimi Räikkönen, 10
2005 Japanese Grand Prix, Kimi Räikkönen, 17
2006 Hungarian Grand Prix, Jenson Button, 14