WOTC - Food poisoning

I asked this question in the Wisdom of the Crowd:

What is the likely cause of food poisoning in Singapore

Here are the responses: (56 Votes)

75 % - Unclean way of preparing the food.
16 % - Contaminated supply of meat and vegetables.
9 % - Shortage of workers and cooks
0 % - Food eaten after the expiry time.

See the pie chart at: 
http://www.wisdomofthecrowd.sg/chart.aspx?ID=1050