What is the origin of the idiom "to the dozen" and when to use it?

The idiom "to the dozen" means at a rate or in a quantity of twelve. The number twelve has historically been used as a standard measure in various contexts, such as dozens of eggs or dozens of items. When "nineteen" or "ten" is added before it, it emphasizes a quantity far exceeding the standard dozen, suggesting an exceptionally high or rapid rate or quantity. This expression is used to describe a situation where something is happening at a very rapid or high rate, often implying that it is difficult to keep up with or control.