Figure 1 displays the number of cases of gastrointestinal illness after the catered dinner, by time of onset. There were 22 individuals that experienced gastrointestinal illness between 17:45 and 21:15. The x-axis is the time of onset in 24-hour time from 16:45 to 22:00. The y-axis is the number of cases, from 0 cases to 5 cases. The time of onset of the first two cases occurred at 17:45. At 18:00, 4 cases started experiencing gastrointestinal illness. At 18:30, 3 cases experienced symptoms of gastrointestinal illness. At 19:00 another 2 cases experienced symptoms followed by one individual at 19:15. Onset of symptoms occurred at 19:45 in 2 cases and another 3 cases at 20:00. At 20:30 another case started getting symptoms followed by one case at 20:45. At 21:00, two more cases occurred followed by the last reported case of symptom onset at 21:15.