Is your source data for the chart the data in the table in the picture? On possible problem may be that you've added an artificial third axis (a.k.a. put the graph in 3D), and the angle you see the column from skews your interpretation of the result, much like if you fill a measuring cup to exactly one cup with water while looking at it with your head level with the markings, then look at the water level compared to the markings from sitting on the floor or from standing up, with the cup on the table.