Understand that the total of all those percentages has to add up to 100. So if your phone is sitting idle a lot, and not actually being used for much, the percentage for application usage and screen usage will drop, and for Android it will go up. Simple math.
That looks to be your situation. If you've gotten nearly a day and still have 39% of battery left it doesn't look like you've used your phone for very much at all during that day. (assuming the stock battery). Tap on the row that says "screen" and see what screen on time is, and do a print screen. Then go back to this screen and tap on the graph, and do a print screen there, and post both images. But if you're running the stock battery and getting a day's worth of usage, I don't think you have any issues.