It changes, there is no one overwhelming effect.
At some times platsplants have dominated at others ocean sediments have dominated. Position of continents, global temperature, sea level, and evolution of lifeforms all effect it.
Also you have a problem that those time periods are time PERIODS, the Proterozoic is 5 times longer than the phanerozoic. It had higher AND lower levels.
https://rock.geosociety.org/net/gsatoday/archive/9/11/pdf/i1052-5173-9-11-1.pdf
https://earthscience.rice.edu/wp-content/uploads/2017/08/Berner_nature-2003-1.pdf
https://www.sciencedirect.com/science/article/pii/S1342937X18302818