I've been noticing a bit of a pattern when being issued a transponder code for local and cross country Flight Following or IFR flight. When doing close in practice work around the home aerodrome, I am frequently issued a code that begins with a zero and sometimes a two. On cross country activities, it starts with a five and ranges from five-two to five-six. 1. Has anyone else noticed similar patterns for their flying? 2. Is there any "if you're doing this, you're gonna get that" sort of logic to transponder codes?