Head to Head Team Lotus driver comparison for 1991 season.
[{'label': 'Mika Häkkinen', 'data': [13, 14, 9, 12, 14, 14, 14, 15, 15, 15, 15, 15, 16, 16, 16, 16]}, {'label': 'Julian Bailey', 'data': [30, 31, 13, 16, None, None, None, None, None, None, None, None, None, None, None, None]}, {'label': 'Johnny Herbert', 'data': [None, None, None, None, 34, 27, 28, 28, None, None, 24, None, 26, None, 27, 27]}, {'label': 'Michael Bartels', 'data': [None, None, None, None, None, None, None, None, 36, 36, None, 37, None, 38, None, None]}]