That's actually a good thing if your screen is not used a lot during the day. I think we're still stuck in the old days mindset of we must kill the top non screen user but Android and the Notes have gotten do much more efficient the numbers can seem deceptive.
If you want a deeper look at what part of Android System is using battery or your battery doesn't seem to be lasting as you think it should, apps like Gsam battery monitor give a more detailed battery usage.
My pre Notes would have things like Wi-Fi, cell standby, Bluetooth, etc fighting for top user and I was lucky to make it through the day without a charge unless I used an extended battery. Now I'm usually no less than 60% left at the end of the day with the same usage. My screen seems more battery hungry since lollipop and I believe it's my auto bright choosing brighter than before in brighter areas. The screen is brighter outside, using more battery.