That also depends on your usage. If you're not using the phone much, System will be a higher percentage. If you're using the phone frequently, then those apps you use will increase their percentage use, and System will use a lower proportion. What may be more useful is to see how much total mAh it's used under "Computed power use" in the battery stats for Android System.
Thanks but even with that battery is draining really quickThat's pretty good. My Nexus 6P running Nougat is currently showing Android System using 354 mAh over about an hour of CPU use (17 hours of the phone being on, a good amount of it in Airplane Mode), with battery down to 67%.
I miss my Note 7 too.
My S7e is a refurb and not brand new, so I do not think I can fairly compare this to my N7, but I can tell you that this battery charges slower and it drains twice as quickly. I do not hate this phone, but I do not love it either. It is real hard to fall for anything after having the amazing N7 taken away.
Go to settings, battery, and scroll to the bottom and look at what is using your battery. Do you see Google photos using quite a bit? It is the number one battery sap on my s7 edge. I'm fighting to disable it completely so it doesn't keep doing this