There are many articles on how people chooses passwords. This article is purely on analyzing PIN numbers. Some observations are obvious but there are quite insightful ones too.
There are 10,000 possible combinations that the digits 0-9 can be arranged to form a 4-digit pin code. Out of these ten thousand codes, which is the least commonly used?Which of these pin codes is the least predictable?Which of these pin codes is the most predictable?
Source: PIN number analysis