I have an Excel spreadsheet that contains hundreds of rows of data that each represent a single sample in a larger population. Each row is divided into three columns that contain frequency counts of a specific type of thing. Together the three columns summed on a single row represent 100%, though each row will sum to a different value.

What I'm most interested in are the proportions of each of these types (ie. percentages of each column relative to the sum of the three columns). I can easily calculate this on a per-row basis, but what I'm really interested in is trying to find an overall trend from the entire population.

I don't really spend much time doing data analysis so the only thing I can think of trying is to create those percentage columns and then average them, but I'm sure there must be a better way to visualise this.