It is very difficult, if not impossible to make any sort of inference based on a single data point.
Psychology is the investigation of behavior that occurs regularly.
Use Winnipeg murder frequencies for the last few years as a basis for talking about what can reasonably be stated based on a single number, or even a set of numbers. It's difficult to interpret what any one statistic is saying. But even inferential stats must be interpreted by someone who knows their language. Descriptive statistics are the numbers that describe the phenomenon of interest. Typically, they are simply measurements or counts.