This photo belongs in econometrics classes.

A perfect normal distribution. Most people stayed around 34-40 kg, and usage naturally fades toward both extremes.
The funniest anomaly is 100 kg being used more than 95. Round-number psychology is real. 95 means nothing to most people, but 100 feels like a milestone.
The lowest hole being overused is another funny signal, some people definitely did the in-out move just to look stronger 😂
Money works the same way. People are naturally drawn to round milestones even when the real difference is meaningless.