Statistics can be deceptively persuasive. You see, when we understand a statistic and just about any bit of a social science for that matter, we feel like we have some authority to make decisions based on that understanding. Hey that is perfectly natural. When it comes to statistics, however, this can be dangerous. Alright so it is not necessarily physically dangerous all the time, although it may be. Let me explain.
When we come to attempt to understand criminals and their behaviour many people will cite information from demographical studies. These studies have an explanatory power to tell us what to expect from people of a demographic; this should not be mistaken for having knowledge of any individual of that demographic. By the nature of justice and by the working definition we have of each other (fully mentally aware, adult, human beings) agency is a necessity. We take this agency away when statistics are used to explain an individual. Basically, it dehumanizes that person; in other words, rather than providing understanding it detracts it, supplanting understanding with empathy and sympathy, two important forces, but not to be confused with understanding.
Statistics can help us understand groups, but often not individuals.
How does this apply to veganism? Well, that is a good question.