Population standing

Hi,

I took a test where they posted the results in a normal distribution table where I clearly scored behind the mean/peak of the graph with a negative z score.However there is a line over the graph saying “population standing=top X%” where the percentage changes and population standing changes for each test.I really don’t understand the logic,if I stand in the top x>95% why am I behind the mean in the normal distribution table ?

I really wish the whole thing provided more details but clearly it did not.