Here is a list with the relative risk factors:
Custard Cream 5.64
Cookie 4.34
Choc Biscuit Bar (eg: Rocky) 4.12
Wafer 3.74
Rich Tea 3.45
Bourbon 3.44
Oat Biscuit 3.31
Digestive 3.14
Ginger Nut 2.99
Shortbread 2.90
Caramel Shortcake 2.76
Nice Biscuit 2.27
Iced Biscuits/Party Rings 2.16
Chocolate Finger 1.38
Jaffa Cakes 1.16
The message is clear. Stay away from Custard Creams, those fiends!